How can I pay for Amazon vouchers at Fortnite?

How does that work because I do not understand that after trying it often

You probably need to buy Amazon V-Bucks or a Paysafecard coupon. This does not work directly because they want to keep the manufacturers or distributors with their vouchers under them. You can't even come to Origin with a Steam coupon.

As User0100 has already said, go on Amazon and you with the Amazon voucher when you play on the pc ne paysafecard buy, ne psn card if you play on ps4 or ne xbox card when you play on the xbox

Not at all! Amazon vouchers can only be redeemed directly at Amazon.

And PSC is not synonymous with Amazon (more). And for a long time!

PSC does not exist on Amazon (anymore).

Oh, I did not know that