I want to activate my  card $50

Please do not post your gift card code here. It will be removed by the moderators shortly.

You have to redeem the gift card onto your Apple ID account first. click here ➜ How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support

If you cannot redeem the gift card, then see the following support document for what to do. click here ➜ If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card - Apple Support

Merchants have to activate your card. Your receipt from the purchase doesn’t show it’s activated?