If you have French customers, not users. Basically you have to give an audit. If you already have an ISO certication it's no trouble.
Basically, do you know the saying 'never roll your own crypto'? It's a bureaucratization of this saying (to avoid people getting sold insecure crypto). Agree or not on the idea that the government should control that (I'm torn tbh), but it isn't a way to force people into illegality to pressure them.