To configure synchronising your SimpleClinic diary to an external calendar, got to your email address in the top right of the screen -> hover over it -> click on the "Your Account" option from the main Navigational menu.
To synchronise your SimpleClinic diary to an external calendar, click on the Link button for the "Calendar integration" option, and you will be asked to choose which external calendar service to connect to.
Select the external calendar service you wish to synchronise with. This article assumes you are connecting to a Google Calendar account. If you are using iCloud the process is slightly different. You will be prompted for an Apple app specific passwords for your Apple ID. This is not your Apple ID password but an app specific password. This knowledge base article from Apple will explain how to create an app specific password. (https://support.apple.com/en-au/HT204397)
Click the green "Link … Account" button.
Choose which account you wish to synchronise with. Some people may have more than one email/calendar accounts, and all your accounts with the chosen service will be displayed on this screen, to choose the correct account.
Once the chosen account is selected, this needs to be confirmed to allow Cronofy to access your external calendar. Click on the Allow button to confirm and continue.
Click on the Allow button, and the screen returns to the "Your User Account" page, showing the Calendar Integration status as shown below.
Click on the Configure button.
This next step is to link your chosen external calendar to SimpleClinic. Click on the dropdown list and select your external calendar account.
Click on Save to apply the changes.
NB - If you are synchronising your SimpleClinic calendar to iCloud, please bear in mind that it can take about 5 minutes to synchronise events. Other calendar platforms are much quicker to synchronise!