overcharge beyond the active hours limit?

Hi there

I have build an App and is looking forward to make it online in the recent months. I'd expect there will be some amount of users, therefore I'm considering to get the basic or standard plan. As there will be overcharge for plaid plans (rather than just disconnect the server) if the app goes beyond the active hours limit - may I ask for how much is the overcharge, i.e. x USD/GBP per minute/hour above the limit?

Interestingly I did not find the precise answer anywhere.

Many thanks,