You've to integrate Google Calendar API to sync with Google Meet. Please follow the steps below to integrate:
Select your project (1) and click on Enable APIs and Services (2).
Search for Google Calendar API and select that.
Enable the API.
Now you've to create the credentials. To create this, go to the API's description page.
Select this options from here and click on the What credentials do I need? button.
Then you'll get a popup dialog box. Set up OAuth consent screen. Click on Set up.
The OAuth consent screen form will be appear then.
In Publishing status, there has two option. Production and testing.
Production: Your site should be HTTPS for this mode.
Testing: You can use any security protocol (HTTPS/HTTP) in testing mode. But you'll get an another page on authentication for this, which is mentioned in point 13.
Click on EDIT APP button and fill up with your desired information.
Click Save and continue button on Scopes and Test users step. And click Back to dashboard from Summary tab.
Click on the Credentials tab now from left panel. Click on Create credentials button and select OAuth client ID.
Select Web application for Application type. In 'Authorized redirect URIs', you should add this url https://yourdomain.com/index.php/google_meet_integration_settings/save_access_token_of_meet. You'll find this in your integration setting.
After saving, you'll get the Client ID and Client Secret. Add them to the settings and click on Save & authorize.
If you've selected Testing mode in point 8, you'll get this option. Select Continue from here.
On retrieving from API access, please make sure that, status of Google Meet Integration is showing Authorized.
That's all! You've successfully integrate with your Google Calendar. Now you can create meeting with the integrated calendar API.