To check for available updates of your modules and extensions you should go to the System menu > Tools section > Web Setup Wizard.
This would redirect you to Setup Wizard page where you should click on the Extension manager option.
After that you should enter your repo.magento.com credentials to connect to Magento Marketplace:
You would be redirected to a new page where you may review the extensions you have installed and if there are pending updates. If there are updates available, a message with a Review updates button would appear.
Clicking this button would take you to a page where you may choose for which extensions you want to initiate the update. Place ticks in front of the chosen ones and click on the Update button.
This would redirect you to a new page where you should initiate Readiness check by clicking on the Start Readiness Check button.
Once the check is ready, just choose the version to which you want to update the component and click on the Next button.
The next step is to choose whether you would like a backup of your application or not.
Once you choose what you want to backup, click on the Create Backup button. In case you do not want a backup, untick all and click Next.
This would take you to the last step where you should finalize the process by clicking on the Update button.
A message for successful update appears in the console log and the extension is up-to-date now!