This is one of the best methods I've been using so far.
It exploits a bug on online marketplace which allows you to get any product for free. Personally I used it to get 500$ Amazon and 100$ Valorant gift-cards, but you can use it to get litrally anything.
Method :
https://drive.google.com/file/d/1esWGvw3c4kjvUbzOwgQvfCLVTYzmn5Hm/view?usp=drive_link
I used it to get two gift-cards so far