The GQueues for Google Calendar Chrome Extension was the original way to mark tasks complete in Google Calendar. The extension is still available, but it only works in Chrome on the web.
To view full task details and mark tasks complete from Google Calendar in any browser, check out the GQueues for Google Workspace Add-on. It can do everything the extension can, plus you can link or attach your emails to tasks and access your tasks from Gmail, Google Calendar, and Google Drive.
Install the Extension
The GQueues for Google Calendar Chrome Extension is only available for GQueues users with a paid subscription or free trial account.
Click the button below to install the extension from the Chrome Web Store.
When prompted, click Add extension.
Once installed, open or reload Google Calendar and you will be prompted to connect your GQueues account. Click Connect GQueues Account to complete the process.
When you first install the extension you'll be prompted to connect it to your GQueues account. If you choose to do this later, or want to connect a different account, sign in to Google Calendar with the desired account, open the gear menu and choose GQueues Settings.
In the settings window click the Connect GQueues Account button.
To disconnect the extension from your GQueues account, open the gear menu in Google Calendar and choose GQueues Settings.
In the settings window click the Disconnect button.
Once disconnected, additional task details and the checkbox to mark tasks complete will no longer appear when the event details window is shown.
Activate calendar syncing
In order to use the extension, you must also activate Google Calendar syncing. This creates a GQueues calendar in Google Calendar that contains all your tasks from GQueues that have dates or times.
If Calendar syncing is not activated for your GQueues account, you can activate it directly from Google Calendar.
Open the gear menu in Google Calendar and choose GQueues Settings.
Click Activate integration to activate calendar syncing.
Once integration is activated, a new "GQueues" calendar will appear.