How to change the home screen wallpaper randomly
As of iOS 13.1.2 there is no default way of doing this. However, a Photos &amp; Video action called Set wallpaper to will be available in future for use with the Shortcuts app.

This action will allow users to set the Wallpaper for either their Lock Screen or Home Screen from a Photos album (which is what you're looking for) or from an online source.

I will update this answer once that action is available for the Shortcuts app.

In the meantime there are a number of apps available on the App Store that promise to change your Wallpaper. Some examples follow:


Shuffle Wallpapers
Vellum Wallpapers
Wallpapers &amp; Backgrounds: HD
Wallpapers &amp; Background Themes
Live Wallpapers Now


However, my understanding is that most apps use an online resource (a library of wallpapers) from where the wallpapers are downloaded. You'd need to check if any of them allow you to use a locally stored Photos album as your wallpaper source.

Disclaimer: I have not used any of the apps listed above, nor do I have an association with any of the developers. You will need to determine if any of them meets your needs and what cost, if any, they have.