LOG IN to your Caltrics account (‘Forgotten your password?’ is available)
Hover over your logged in account name and click/tap MY ACCOUNT
Click/tap ‘Connect my calendar app‘ and follow the instructions.
You can also click/tap ‘Email my connection details‘ (check junk mail!)
The speed at which the events of the selected calendars will appear in your calendar app will be dictated by the following Refresh frequency of the main calendar apps