If you haven't closed your browser in a while or want to check if an update is available, you can do so manually at the top right of the chrome browser.

Click the three dot icon next to your profile picture.

If there was an update, the icon would be colored green for an update released two days ago.

Orange for an update released four days ago and red for an update released at least a week ago to update your browser.

Select Update Google Chrome in the drop down.

If you can't find this option, that means you're on the latest version.

Click relaunch.

If you don't want to restart right away, click.

Not now, and the update will be applied next time you open your browser.