I’m using SimBrief as well. It’s pretty easy once you know things you should pay attention to.
- I would enter the general flight info (departure, arrival, and aircraft), then.
- Choose a route that doesn’t pass through a conflict area (e.g. Afghanistan).
- Generate.
- Download the Google Map KML file.
- Convert it to FPL here.
- Airdrop it to your phone and choose the FPL from your storage.
- Enter the remaining info (pax, cargo, fuel, etc.) from SimBrief. I also include step-climb altitude(s) in my FPL (see the Briefing Preview section).
I also recommend checking my logbook here, enter all the required info, and everything will be displayed on the settings sheet, including the flight profiles and flight settings. It also automatically calculates your load!