To check which version of Despatch Cloud you are running simply login to your account and from the dashboard scroll down to the bottom of the page where you will find your version number as shown in the screenshot below. If your version number shows as 3.4.X or above your can install automatic system updates using the guide below.
To install your update simply login to your account and from the dashboard click on the settings menu in the top right of the screen as in the screenshot below.
From the settings menu click on the Engineer Menu option as in the screenshot below.
Now click on "Download & Install System Update" as in the screenshot below.