1. Make sure Backblaze is working with Cloudflare. This can be found HERE

  2. Uncomment out the below. I made my Backblaze URL s3.DOMAIN.COM

  3. nano /etc/pleroma/config.exs

     # Configure S3 support if desired.
     # The public S3 endpoint (base_url) is different depending on region and provider,
     # consult your S3 provider's documentation for details on what to use.
     #
     config :pleroma, Pleroma.Upload,
       uploader: Pleroma.Uploaders.S3,
       base_url: "https://s3.DOMAIN.COM/file"
     #
      config :pleroma, Pleroma.Uploaders.S3,
        bucket: "BUCKET_NAME",
     #   bucket_namespace: "my-namespace",
     #   truncated_namespace: nil,
        streaming_enabled: true,
        strip_exif: true
     #
     # Configure S3 credentials:
      config :ex_aws, :s3,
        access_key_id: "0000000000000000000000000",
        secret_access_key: "AAAAAAAAAAAAAAAAAAAAA",
     #   region: "us-west-002",
        scheme: "https://"
     #
     # For using third-party S3 clones like wasabi, also do:
      config :ex_aws, :s3,
        host: "s3.us-west-002.backblazeb2.com"
    
  4. This should now allow you to upload files and should display the file from https://s3.DOMAIN.COM