How can I allow my son to redownload previously purchased or free apps without requring him to sign in?

My son's old iPad was set so that he could re-download anything that was previously downloaded without needing to enter the password.

I want the password to be needed for anything new (free and purchased).

He just got an iPad 7th generation. I am not sure what iOS it has, the newest version as of 7/13/20.

Thanks!