Which App Store app should you use to reset your Apple ID password when you...

Apple Support is a free app that helps you access personalized solutions for all of your Apple products and services, including AppleCare+ plans. You can also talk to a real person, book a reservation, find a nearby store, and manage your subscriptions. One of the features of the app is to reset your Apple ID password with the Apple Support app on a borrowed device. If you don’t have an Apple device but have access to your trusted phone number, you can borrow an Apple device from a friend or family member, or use one at an Apple Store. You can open the Apple Support app on the borrowed device, scroll down to Support Tools, tap Reset Password, tap “A different Apple ID”, enter your Apple ID, and follow the onscreen instructions to reset your password. Any information that you enter will not be stored on the device. References:

Apple Support on the App Store

If you forgot your Apple ID password - Apple Support