In Navigraph Hub, in MSFS 2020 tab, Install SimBrief Dispatch for MSFS 1.3.0
In MSFS 2020 World Map ,Choose SIMBRIEF
Enter your SIMBRIEF Pilot ID
Create or edit a flight plan. Make sure you then press Generate Flight.
You should be able to Import Flight
Depending on which aircraft you should be able to import the flight plan using EFB and FMC/MCDU.
Cheers
Ian