cancel a child's subscriptions?

With restrictions (ScreenTime) enabled for a child's iPhone who is on a family account. I, the parent manage the account. How can I manage subscriptions that he has like Roblox. I don't see where to edit these. I have to disable restrictions, log into his app store on his iPhone, then go to subscriptions to edit. Since I manage the account as the parent, is there an easier way I can manage this, because now I hav to go back in and reenable screen time restrictions any time we want to make a change on his phone.