No, sorry, but once you have approved the app, it is added to the child's Apple account purchases. Purchased items cannot be completed removed from the account that it is tied to. There is a way to hide it, and set Content & Privacy Restrictions so that it is no longer accessible to the child however:
Hide iOS apps
- Open the App Store app, then tap Today at the bottom of the screen.
- Tap
or your photo in the upper-right hand corner, then tap Purchased. If you use Family Sharing, tap your name to see only your purchases. - Find the app that you want to hide, then swipe left on it and tap Hide.
Once you have hidden the app, then under Screen Time, make sure a password that only you know, turn on Content & Privacy Restrictions, then tap on "Account Changes" under the "Allow Changes" section, and tap on Do Not Allow.
This will remove the
from the Today screen, so they will no longer have access to their Apple account where you would have to go to unhide the purchase.
Here is a link to the hiding and unhiding article that shows you the path for unhiding that I am referring to. This path will no longer be available once you have followed the steps above.
Best,
GB