So, dumb question inbound. I have only been on MSFS since last October. I have been strictly GA and Corporate type flying. I am now starting in commercial ops. I fly only on Vatsim. I see that you call jetways in MSFS via the ATC menu and tuning ground? But if one does not use the default MSFS ATC and does not use GSX (had it in P3D, don't care for it anymore), how does one call for the jetways to connect / disconnect from the aircraft? I have FSCrew Pushback for that part of the operation, just wondering on the jetway part? Thank you  

You can still bring up the ATC menu, tune ground and then request jetway connection. You dont need a flightplan or have already been using default ATC for it to work.

What aircraft are you flying?  Most of them have a way to request the jetway either in EFB (FBW & Fenix) or in the FMS options (PMDG).