you need to explain me how i would scam someone when i am the one buying this giftcard online ...
and that i will give this code to the lender and he can redeem it BEFORE sending me any loan
So you're selling him the Steam code?
Because if it's a collateral, the lender is supposed to send it back to you after you repay the loan, no? How can he do that after already redeeming the code?
So, for you question... "a gift card (steam) is accepted as a form of collateral for getting a loan?", the answer is technically no.