Cool that they started a repu airdrop, I am very happy about it.
I just do not unterstand the google forms.
What does "Your Referral Telegram Username (optional): @" mean? Do I have to enter again my telegram name? Does this activate the refferal program?
It means you must put the telegram username of the person who referred to you about the airdrop or leave it blank if anyone did not refer you.

hmm ... but there are two fields, I dont understand the difference.
Your Referral Telegram Username (optional): @Answer below if you were invited by a friend ONLY!
Enter your friend's telegram username, who invited you to join and get 10 REPU tokens each!
Your Friend's Telegram Username (Referral): @The first one decides probably which name you want to use for getting refs yourself, so which other people have to use. So it could be different from your registered name in the first place. The second one is for the person who gave you the link, so to put in his/her name.