i want to ask how many tokens are sent to airdrop participant every round?
It depends actually. If you new to airdrops it's something like 150 coins. If you had airdrop before and you hold 90% of coins then it's something like 800 per person. Check discord, there is all rules and explanations to be sure.
is the airdrop participant must use their signature?
I'm interested to join but just that rules that i can't do
If you are not allowed to display a signature due to the new BCT rules we will not penalize you for this. Just follow all other requirements other then the signature, and you'll be ok. Your BCT account must still be created prior to 6/1, with 28 activity, but the signature doesn't have to be displayed (only if it CAN'T. If you are able to display a signature, you MUST STILL) Try to make some high quality posts, it isn't as hard as you may think to make a merit worth post. Best of luck to you, and have a great Airdrop!