The latest firmware listing can be found on the PMI webpage under the Support page or directly at: https://powermonitors.com/firmware-chart/
You can see the recorder Firmware version on the header reports in Provision.

In Provision, if you have a recorder connected to your PC, you can visit the Recorder tab and select Identify, then select the View button that pops up.

In the listing that displays will be the Firmware of the recorder.

In Provision the Upgrade Manager, keeps the latest firmware on your PC up to date. Your IT can block this feature.
Select the Help tab in Provision, then select ‘Check for updates’

In the Firmware section of the popup, it will display how many Firmware files are not on your PC.

Allow the Upgrade Manager to load the missing Firmware files on your PC.

Provision will compare the Firmware on your PC to any recorders that are connected. After a download of the data file, Provision will ask if you want to update the Firmware if the Firmware is different.

How to manually update Firmware in an Attached Recorder 

Connect recorder
In Provision select Options -> Show Advanced Operations

In Provision select Recorder -> switch to standby mode (if shown)

In Provision select Recorder -> Upload firmware