Application User ID
User ID Usage
User ID is a unique Identifier that differentiates between your different users. ironSource uses the User ID to know which user to reward upon successful ad completion through server-to-server callbacks.
Create a User ID
When creating a User ID, make sure to use a unique string for each of your users, in a string format, using up to 64 alphanumeric characters.
Read more about end-user flagging below: