Update Raspberry Pi system

I am having a problem with a Raspberry Pi4 installation that I believe requires a server software update.

My other installations are Mac based and I know how to update the server software from the Mac, but I do not know how to update the Raspberry Pi4 server.

The Raspberry Pi4 system services an AppleTV app and an iPhone app. A MacBook is on the same network.

How can I see which Channels DVR server version I have and check for an update for the Raspberry Pi4 system?

You should be able to access your RPi4 server using a web browser of a device connected to the same network.

http://RPi4 server IP address:8089/admin/settings

Pi server is updated same as any Channels server.
Go to the web UI of the server...and click the update button.
If you are using the dedicated Pi image for Channels server, then you have the top section to update the OS of the server, with the second section to update the server it self.

Thank you mjcxp and speedingcheetah. I was blind to the obvious.