In the main product screen you will see the topology off your network. Scroll up on the workspace main to view its options. 

Select Update and all devices that need to be updated or are up to date will show the firmware they are on or the firmware they need to be updated to.

If you are not sure whether the update is a valid one you can always look up the firmware on Reyee website

 https://www.ruijienetworks.com/products then you would find your device and scroll half way down to the Documents section and check the current firmware. If more current firmware then need to be on the cloud or IP to download the most current firmware

Note: The true firmware will not take you to a document instead it will simply say download