Can I use CBX to cross the border to Tijuana if I do not have flying inside Mexico?

You need a valid cbx ticket and a valid boarding pass in order to use it

No: CBX airlift is only for passengers with a valid boarding pass for a flight leaving TIJ or arriving there within the next 24 hours.

What is needed to go through the cbx to tijuana apart from the boarding pass

You need to have a boarding pass to be able to do cross border

I don't think so. You need to come from a plane or have a flight to go

You need your boarding pass to be able to cross, both roundtrip

Very good.