Instructions
NOTE: The app that you wish to use as your default browser must support this feature. (If the option does not appear and you have the correct operating system, contact the app developer to request that they add support for this feature.)
1) Open the Settings app.
2) Scroll down and tap the name of the app that you wish to set as your default browser.
3) Tap Default Browser App.
4) Tap which app that you wish to use as your default web browser.
Outcome
Your default browser for iOS or iPadOS has been configured.