In which case Forge should already have added your SSH key for you - it does so for me. Have you since changed id_rsa or id_rsa.pub manually on your server?
It doesn't added the key for me, only created one when I use bitbucket to add the repository (different from the id_rsa that I created to connect to my Digital Ocean servers).
Seems to be the env variables used to connect to the forge@servername database.
If I have working inside my dev machine, how can I configure environment variables to production?
Yeah, when you edit your .env vars within Forge you can deploy fine.
I copy all my .env vars to the Forge .env file but something I don't understand, why is used APP_ENV=local as well in the Forge environment and it does work?