ROVL installation

Hi, I’m trying to use a ROVL MK II autosync but the software CeruleanTracker always have the same warning: “We are not detecting the ROVL transmitter”.

I am a bit lost…Having the autosync version I have a couple of questions:

Is it mandatory to use GPS? (I have read somewhere that sometimes it is not necessary)

In the transmitter is it enough to have only the power? That is, with the TX and RX serial cables disconnected?

What power supply is correct for the transmitter? 12V, 9V or 5V?

Thanks!