How to use gift card for Apple TV as Android user?

Installing iCloud is not going to let you redeem a gift card in any way.

On a Windows PC install iTunes, the Apple Music or TV apps and follow the steps in the support document linked below.

click here ➜ How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support

Install Apple Music or Apple TV for Pc Windows 10 o Windows 11 and log in with the Apple 🆔 then redeem that Apple gift card since you need a Apple 🆔 to log in to Apple TV + whatever you do in that account will be synced too and you can use for Apple Music etc etc

Redeem a gift card on a Windows PC

1. Find the 16-digit code on the back of the card. For some gift cards, you might need to peel or gently scratch off the label to see the code.
2. Open the Apple Music app or Apple TV app.
3. Click your name at the bottom of the sidebar, then click Redeem. You might need to sign in to your Apple Account first.
4. Follow the instructions on screen, then click Redeem.
5. 
   
6. 

No where says iTunes in this link

How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support