Exactly!

I am a writing coach, and I will happily reschedule a session if you give me some advance notice.

Even an hour's advance notice.

But if you ghost me?

I'll charge you a $50 cancellation fee and won't reschedule until you pay it.

But I'll waive that fee if, for example, you can't make the session because you've had an accident and are in the hospital, or because you managed to drop the phone we were going to talk on out of the kayak and into the lake.