Is there a way to lock the volume on an iPad?

I have an ASD son who listens to his iPad 100% volume. 7am-1am. I need a way to make it permanently one volume. If you turn it down he turns it back up and disabling the buttons does nothing because he doesn’t use them in the first place, he always moves it in the control center. I tried downloading “volume limit” but it was to be running in the background to work and he knows he can just clear it out and be done with it. What can I do????

[Re-Titled by Moderator]