For your customers
Every confirmation includes an add-to-calendar link, so the appointment lands in whatever calendar they use.
For you
Appointments can be downloaded as a calendar file and added to Google Calendar, Apple Calendar or Outlook.
What this is not
It is a one-way copy, not two-way sync. Busy time in your personal calendar does not block your OperMae availability — block that time under Schedule → Block time so customers cannot book over it.
The reliable view
Schedule → Calendar in OperMae is always current. Treat a copy in another calendar as a convenience.