Ah, I forgot to add the error message...
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: botocore.exceptions.ClientError: An error occurred (403) when calling the HeadBucket operation: Forbidden
fatal: [minecraft]: FAILED! => {"boto3_version": "1.20.37", "botocore_version": "1.23.37", "changed": false, "error": {"code": "403", "message": "Forbidden"}, "msg": "Failed while looking up bucket (during bucket_check) artifacts.: An error occurred (403) when calling the HeadBucket operation: Forbidden", "response_metadata": {"host_id": "", "http_headers": {"connection": "keep-alive", "content-length": "209", "content-type": "text/xml; charset=utf-8", "date": "Tue, 18 Jan 2022 07:22:01 GMT", "server": "nginx/1.20.1"}, "http_status_code": 403, "request_id": "", "retry_attempts": 0}}
I know that a 403 means forbidden, but I really don't get it. Everything is reachable from my server.