Google Calendar Import Error: 404, 403 can be resolved quite easily, for that follow these steps. You can check to see what are you missing, watch the video in this link : https://www.webnus.net/dox/modern-events-calendar/video-tutorials/ or This Video .
- The Google Calendar should be public to import
- The timezone on WordPress and Google Calendar need match together
- APIKey should be enabled for Google, check the client ID too
Cron Jobs, check these items :
- Import manually for the first time so the API would be set in MEC.
- Go to MEC Settings > Import/Export > Synchronization Tab, and copy the URL it provides.
- Go to your site CPanel and use this URL in cron kobs
Please Note: Cron jobs is a feature of CPanel and you need to contact your host provider to set it.