We don't have a complete list of LVARs available; however, there are tools available in the simulator if you would ever like to find them yourself.
In MSFS 2024, if you go to MSFS Settings > General > Advanced Options, enable Developer Mode and then load a flight in the aircraft. Once loaded into a flight, move your mouse to the top of the screen and on the black menu bar, go to Tools > Behaviours. With this menu open, move your mouse cursor over any control in the cockpit and then press [CTRL] + [G] on your keyboard. This will then populate the LVAR name into the "ID" field in the Behaviours window.
For the controls you are asking for, the LVARs are as follows:
Fuel Lever Left: F28_PED_L_FUEL_LEVER
Fuel Lever Right: F28_PED_R_FUEL_LEVER
Flap Lever: F28_PED_FLAPS_LEVER
The F28 also supports MSFS control assignments for the above controls. Any of the FLAPS control assignments should work to control the flaps, plus the FUEL VALVE control assignments should work to control the fuel levers.
Hope that helps.
Mark - Just Flight