In order to configure Contacts and Calendars synchronization on your Thunderbird (Email Client) on your Desktop, you will first need to install the extensions named TbSync and Provider for CalDAV & CardDAV.
If you do not know how to install extensions, check this article out.
Before we start, make sure that your domain is using the appropriate hosting nameservers, since the method we are using in this article takes advantage of the AutoDiscovery method for the calendar URL.
1. Open your Thunderbird, and access the menu option Tools → Synchronization Settings (TbSync):
2. Click on the Account Actions → Add new account → CalDAV & CardDAV.
3. Leave the default option ticked – Automatic Configuration.
4. You’ll now be asked to fill in 3 fields:
Account Name: Any description that you want. Example: Epik Calendar
Username: Your full email. Example: email@example.com
Password: The email account password.
5. Confirm the information looks alright, it should be something like this:
6. To enable the syncing, select which calendars you want to sync and click Synchronize Now.
7. Done! Now you just need to access the calendar by going into the menu option Tools → Calendar, and you’ll see your new calendar with all your events.