- Navigate to https://calendar.google.com
- Click the Chrome drop down menu > More Tools > Create Shortcut
- Rename to "Google Calendar" and check "Open as window"
- Open the new Google Calendar app
- Right click on the app > Options > Keep in Dock
Source: https://apple.stackexchange.com/a/393180
If you'd like to create a Google Calendar app for a secondary account (e.g. school, work, etc.):
- Open Chrome Devtools