If the referrer has changed their username since sharing their referral link or code, then you will need to get a new referral link or code from them that reflects their new username.
This is because their username is their referral code. The format of referral links is https://myprize.com/invite/username.
Therefore, if the referrer changed their username after sharing their referral link, the old referral link will no longer be valid.
As a result, we recommend choosing a permanent username before sharing your referral link. Learn more about usernames here.