Error We were unable to install a project on your server

I'm running a server on DigitalOcean and used Forge to setup the server. The server is up and running. When I try to create e new site by cloning a repo from Github to the server I always get an error. The log is below. Please bear with me, it's my first time to deploy an app. Could someone help me what the problem is? Thanks in advance!

We had trouble connecting to your server. Typically, this means there is a problem with the SSH keys on the server. Or, your server may be prompting for a password when Forge attempts to SSH in as the root user.

Error Output

rm: cannot remove ‘/home/forge/default/public/laravel/gulpfile.js’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/readme.md’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/factories/ModelFactory.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/migrations/2014_10_12_100000_create_password_resets_table.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/migrations/.gitkeep’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/migrations/2014_1012000000_create_users_table.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/seeds/DatabaseSeeder.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/database/seeds/.gitkeep’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Exceptions/Handler.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Events/Event.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/User.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Policies/.gitkeep’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Jobs/Job.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Console/Kernel.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Console/Commands/Inspire.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Providers/EventServiceProvider.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Providers/RouteServiceProvider.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Providers/AuthServiceProvider.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Providers/AppServiceProvider.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Listeners/.gitkeep’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/routes.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Controllers/Controller.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Controllers/Auth/PasswordController.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Controllers/Auth/AuthController.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Requests/Request.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Kernel.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Middleware/VerifyCsrfToken.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Middleware/Authenticate.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Middleware/EncryptCookies.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/app/Http/Middleware/RedirectIfAuthenticated.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/.gitattributes’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/phpunit.xml’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/tests/TestCase.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/tests/ExampleTest.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/composer.json’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/artisan’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/bootstrap/cache/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/bootstrap/app.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/bootstrap/autoload.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/mail.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/filesystems.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/compile.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/services.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/view.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/cache.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/database.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/auth.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/session.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/app.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/queue.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/config/broadcasting.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/package.json’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/vendor/vlucas/phpdotenv/README.md’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/vendor/vlucas/phpdotenv/LICENSE.txt’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/vendor/vlucas/phpdotenv/composer.json’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/vendor/vlucas/phpdotenv/src/Dotenv.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/vendor/composer/f1ce307a/vlucas-phpdotenv-0cac554’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/framework/sessions/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/framework/cache/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/framework/views/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/framework/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/app/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/storage/logs/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/assets/sass/app.scss’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/views/errors/503.blade.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/views/vendor/.gitkeep’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/views/welcome.blade.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/lang/en/passwords.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/lang/en/auth.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/lang/en/validation.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/resources/lang/en/pagination.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/.gitignore’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/phpspec.yml’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/server.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/.env’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/public/robots.txt’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/public/index.php’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/public/favicon.ico’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/public/.htaccess’: Permission denied rm: cannot remove ‘/home/forge/default/public/laravel/.env.example’: Permission denied