Please follow the below steps to upgrade Joomla extensions:
Log in to Admin panel
Extension > Extensions Manager.
Click on an update.
You will see the list of extensions whose new version are available
You need to click on the update button beside the extension you would like to update.
Note: the Joomla extensions can't be refreshed through the Joomla Extensions Manager. Along these lines, it is essential to check the authority sites of the extensions that you are working with. It is desirable to buy into their RSS channels for getting told about the new forms once they are accessible.