If you use a vivo phone, the method to set the default program is as follows:

OriginOS/Funtouch OS 4.0 and above: Settings--Applications and Permissions/More Settings--Permission Management-- Permissions--Default application settings

Funtouch OS 3.0 and 3.2: Settings--More settings--Applications--Default application settings.

Funtouch OS 3.0 or below: iButler--Software Management--Default Software Settings.

The default programs that can be set are: input method, desktop, browser, photo album (gallery), music, video, message, and email.

Note: The camera default program only supports settings below Android 11.