Here's how to release one song ahead of an album drop.
Just upload the single first, and then upload the entire album (including the single) as a separate release later on. Once the full release is in streaming services, you can choose to leave the single, or remove it and only have the album version available.
Note: If you use your existing ISRCs, the exact same audio file as in your original upload, same metadata (track titles, artist name, etc.) this might help retain play counts/playlists for the single in some streaming services. This does not always hold true for all cases.
Please send us a request for song codes and alert us to match them to the songs in your album release.