First time selling, did I get scammed? Or?...

Basically I posted a Walmart gift card I didn’t need for sale, I had auto delivery set up so the person automatically get’s there card. The item sold and the gift card got redeemed (https://gameflip.com/item/-77-61-walmart/5ed4d9c5-ef94-4687-957c-3561b3f2218d). The automatic system then sent me a email saying his gift card was sent and I have to await for him to accept?!?! So basically he can claim it didn’t work and run off with my gift card? I tried messaging the buyer asking for him to confirm it worked and he hasn’t responded. Help anyone?!?

I think there’re always some risk for both sellers and buyers so we need a middleman to jugde.
In this case I think your buyer is also a new user so he didn’t know that you won’t get your money if he would not rate you.
Beside, if there were a dispute both side have to provide evidence to proof they are not scamming so don’t worry.

also, he has 3 days to accept trade. If he dont do this, you will get your money after this period of time.