How can i pay Netflix using my apple gift card

This depends on the country that your are from.

You can use Apple Gift Card to purchase products or accessories at an Apple Store.

In countries and regions where Apple Gift Card is available, you can use your Apple Account balance to buy products and accessories at apple.com or in the Apple Store app. In these countries and regions, your Apple Account balance includes the balance from any Apple Gift Cards or App Store & iTunes Gift Cards that you have redeemed.

What you can buy with your Apple Gift Card or Apple Account balance - Apple Support (IN)

Hello,

Which type of Apple Gift Card do you have? Only two of the types can be used in the App Store.

What type of gift card do I have? - Apple Support

What you can buy with your Apple Gift Card or Apple Account balance - Apple Support

"Some purchases might require that you have a credit card on file, even if you use your Apple Account balance to make the purchase."

I hope this helps.