The Apple Artist ID is automatically assigned to each artist that has uploaded to the iTunes Store and Apple Music.
For Artists who already have content on iTunes or Apple Music, they can enter their Apple IDs on Too Lost. This will prevent content from being delivered to the wrong artist page.
Once the works of an artist are available, the artist ID can be obtained via Apple's artist page.
To obtain the artist ID follow the following steps:
1) Search any album or artist on iTunes
2) Click on artist's name to visit their artist page
3) The ID appears after the letters "id" on the url (example: 262836961)
The format of an Apple Artist Page URL is:
https://itunes.apple.com/us/artist/[ ARTIST NAME ]/id[ ARTIST ID ]
NOTE: Make sure that the URL is the artist page, not the album page.