This is the most cases of scam nowadays like they want the user to send first their money before they give the airdrop or giveaway. You can definitely see this kind of giveaway scam on twitter and telegram, then I guess there's someone who still falls on this especially the newbie who just enters on this field. I know there's some legit giveaway but in order to obtain the prize, you need to do something like in Binance exchange where they launch community giveaway then you just need to trade 1 bitcoin before you become part of the giveaway.

If you see this kind of giveaway I suggest that you should avoid it because you're just wasting your money and time. Then, if you're going to participate in some giveaway make sure it is legit and not a scam. Always remember to make your research so can know what to do if you encounter this kind of scam.