Click on the upper left three "bars" to open the menu
Open the settings
Here you can see the installed version
To find out if the latest version is installed (on your smartphone), have a look at the "Release Notes" in this documentation or you can try to do an update (next section)
How to do an update?
Which operating system are you using?
Android
Start your browser on the phone (if you want to browse the internet. Depending on the device its either called "Chrome" or simply "Internet")