This article explains how to change default apps on iOS 14 and later.
iPhone How to Change Default Apps
The word “stock” means two things when it comes to iPhone apps. First, it means the apps that come pre-installed on your iPhone when it ships from the factory (or when you reset the phone to factory settings).
In the second case, default apps are apps that are always used to do a certain thing. For example, when you tap a website link in an email, it always opens in Safari. That makes Safari the default web browser on your iPhone. When a website contains a physical address and you tap it to get directions, Apple Maps launches because it is the default maps app.
Many apps do the same thing. Google Maps is an alternative app for navigation. Many people use Spotify instead of Apple Music to stream music. Others prefer Chrome to surf the web instead of Safari. Anyone can install these apps on their iPhone. But what if you always want to use Google Maps instead of Apple Maps? What if you want links to open in Chrome every time?
