How do you start the Ardor funding account monitor via the command line? I want to fund accounts I tag via account properties using the account monitor, but I want to understand how it can be started. 

The ardor account monitor can be started via the gui: https://ardordocs.jelurida.com/Account_Monitor


When starting the monitor via the GUI, do you have to leave the browser open?
What about starting it via the command line? 
Also how does fee-ratio work? Is there an example?
There is no specific command line option to start the funding monitor. 
You can probably start it using a curl command after starting your node.

Q: When starting the monitor via the GUI, do you have to leave the browser open?
A: You can close your browser just keep your node running like with forging and bundling.

Q: Also how does fee-ratio work? Is there an example?
A: Fee ratio works like in any other API it is the conversion rate between child token and parent token used when the monitor submits its funding transactions.