https://app.binance.com/uni-qr/cpro/Square-Creator-f90031505saifbi?l=en&r=498940351&uc=app_square_share_link&us=copylink fol low me

Hello guys,
I am using web3 for the first time. And I don't have much experience. I sent usdt to my wallet via poly network and I have money left here. I think I need to pay gas fee to withdraw it but I can't do that. I need to buy poly for gas fee but I have no idea how to do this. Can you help me? Thanks.