Hi Madaaalinaaa,
I understand that when trying to download apps, your iPhone asks for Touch ID, then your password, and repeats this process. I'm happy to provide some help for this issue.
I recommend first forcing the App Store to close, and then restarting your iPhone:
How to force an app to close on your iPhone, iPad, or iPod touch - Apple Support
Restart your iPhone, iPad, or iPod touch - Apple Support
If you continue having this issue, make sure that you do not have any outstanding billing issues that could prevent you from downloading new apps:
If your payment method is declined, or you have a billing issue with a previous purchase in the iTunes Store - Apple Support
And sign out of your Apple ID and back in again if this isn't the case. To sign out of your Apple ID:
- Go to Settings.
- Tap [Your Name].
- Tap iTunes & App Store.
- Tap your Apple ID.
- Tap Sign Out.
To sign in with your Apple ID:
Sign in with your Apple ID - Apple Support
Before you begin, update your device to the latest iOS.
When you use iOS 10.3 or later, you sign in to iCloud, the iTunes & App Store, iMessage, FaceTime, and your other Apple services in one place.
- Go to Settings.
- Tap Sign in to your [device].
- Enter your Apple ID and password.
- If you protect your account with two-factor authentication, enter the six-digit verification code and complete sign in.
Thanks for using the Apple Support Communities. Cheers!