You can get a URL to subscribe to your Cambly schedule on your Priority Hours page. The URL will add your Priority Hours along with your pending and confirmed Reservations.
Some calendar application will allow you to select how often the calendar refreshes such as Apple Calendar, but other Calendars (Google, Yahoo, Outlook) will refresh at an interval which you cannot change (still, they should refresh at least daily).
Different calendars use different methods for adding a URL. Some of the most common instructions are listed below:
Outlook Web (under "Add an Internet Calendar Subscription to Outlook")
Google Calendar (under "Add using a link")
Yahoo Calendar (under "Follow other calendars")
Note: Since each calendar application refreshes the calendar at different times, the URL might not always have the most recent information (if you cancel a Priority Hour or Reservation, it might take a while to see that reflected in your calendar application). Always check the Priority Hours and Reservations pages for the most up to date schedule if you have any doubt.