It reminds me the scam scheme of donating to receive a bonus for the donation you have just done. It's definitely not a giveaway or airdrop, as such offers don't involve the participants having to give money from their own pockets to participate. These offers can demand you to complete a task, but you give only your effort in counterpart for the final payment. Even if you hear some people saying it's legit, I believe it's not a good idea to join, because there is a high chance it's a ponzi scheme.
Unfortunatelly crypto industry is full of scammers and I risk saying there are more scammers than ever right now. Very few offers are legit these days and worth to be executed for small amounts of profit.
It may ring a bell or two for everybody involved, and it's everybody's responsibility to look into any project that may request additional funds to be even eligible or to get bonuses from it.
It may turn out badly in the end, though, it all depends on the credibility of such a project and who supports them, with who they collab, etc.