meetergo supports the connection of CalDAV calendars. This is a great way to connect your self-hosted calendars.
Here's how it works
Log into your meetergo account and go to the profile settings.
On the right under Calendar Sync, next to CalDav, click Connect.
Enter the corresponding server URL (e.g. https://meinedomain.de/caldav/1234) and your login data.
Click on "Add connection"