Unable to write file at location in spatie google cloud storage laravel

I'm trying to upload file on my google cloud storage using https://github.com/spatie/laravel-google-cloud-storage but unfortunately Im getting an error. Please see my code below together with the error Im getting.

filesystems.php

'gcs' => [
         'driver' => 'gcs',
         'key_file_path' => env('GOOGLE_CLOUD_KEY_FILE', null), // optional: /path/to/service-account.json
         'key_file' => [], // optional: Array of data that substitutes the .json file (see below)
         'project_id' => env('GOOGLE_CLOUD_PROJECT_ID', 'your-project-id'), // optional: is included in key file
         'bucket' => env('GOOGLE_CLOUD_STORAGE_BUCKET', 'your-bucket'),
         'path_prefix' => env('GOOGLE_CLOUD_STORAGE_PATH_PREFIX', ''), // optional: /default/path/to/apply/in/bucket
         'apiEndpoint' => env('GOOGLE_CLOUD_STORAGE_API_URI', null), // see: Public URLs below
         'visibility' => 'noPredefinedVisibility', // optional: public|private
         'metadata' => ['cacheControl'=> 'public,max-age=86400'], // optional: default metadata
         'throw' => true
]

Error