Installing Apps on Child's Apple Watch When Managing as Family

My son received an Apple Watch and he does not have an iphone. I set up his watch with my iPhone using these steps (setting up for a family member).

He wants to install some apps (Spotify for one) from his watch, but it's indicating "Requires iphone" when trying to install. From my watch app on my iphone I do not have the option of installing additional apps. Also the setting page looks very limited, compared to others who have their watch paired to their iphone (direct vs setting up for a family plan).

Just spent 2 hours with apple support, and was told that the watch will have more restrictions and apps that cannot be installed when set up as a family plan.