Show your Repender appointments in the calendar app you already use, such as Google Calendar, Apple Calendar or Outlook. Any app that can subscribe to a calendar by link works. The calendar is part of the Plus and Pro plans.
Copy the link on the Calendar card under Settings, then Integrations, and add it to your calendar app as a subscribed calendar. The card has instructions for Google, Apple and Outlook. The link is for the shop you have open, so with more than one shop, switch shops to copy the link for another one.
Changes only go from Repender to your calendar app, not back. Your calendar app decides how often it refreshes, so a new appointment can take a while to show up. Anyone with the link can see your appointments, so keep it to yourself. You cannot create a new link or turn the old one off yourself. If the link ended up somewhere it should not be, contact support.