The 6-8 ID number is the unique number associated with an Athlete Profile on the 6-8 app. To find this number, click on "Athlete Profiles" within your 6-8 app account and then on the name of the Athlete. The 6-8 ID is the number that appears under their name.
If you need a 6-8 ID number but don't yet have the app, please download the 6-8 Sports App from the iTunes (Apple) or Google Play (Android) stores. Once you have the app, you first need to create a user account. Once you do that you can create an Athlete Profile for yourself (or others) within that user account.