OK, yea you need H-E-N or USBcontrol to get that working, this is not USB OTG..... Is there a keyboard shortcut to open and navigate the settings tray?
I think there is but I cant get my N900 to boot right now. try these form https://www.fonearena.com/blog/9398/...shortcuts.html
Maybe try to pair a bluetooth mouse and use keyboard to tab to accept the pairing? It is a real problem to get input here, especially since I am not sure how to get into the settings tray with a keyboard assuming you have USB OTG installed.