I saw some folks were missing where to find the old FS’20 W&B / Fuel applet in the new sim. If you’re like me and the flight planning phase is not working for you or is frustrating and you finally get the plan loaded, the plane where you want it on the field and get airborne - only to realize you forgot (or somehow it reset) the fuel state, you can open the EFB in-flight and fix all that.
Just go to the Aircraft tab (airplane icon lower left), pick the Flight Performances section, then Mass and Balance. Adjust as you need. Check your Fuel Quantity in-cockpit. Voila.
Note: Tested only in Free Flight. I don’t fly Career.