ken h wrote on Dec 30^th, 2022 at 9:23pm:

what is the path for putting flightplans from simbrief in the L1011?

As far as I know, the L-1011 won't recognize a Simbrief Plan, so what you need to do is this:
Save the Simbreif Flight Plan to the Documents\Prepar3D v5 Files folder
Open it with the default P3Dv5 Flight Planner
You then have to save it as a default Flight Planner file (.pln) so it can be loaded into the L-1011 INS Control Display Unit.
Once you've done all that you should be good to go.