Are you talking about the "lever" to pop open the fuel tank cover? If so, have someone pull the lever and you go check whether the small arm moves or not on the inside of the cover itself. If it's not moving, then perhaps cable got disconnected somewhere.
I don't think it's something serious but if the cable alrdy snapped, then it's quite tricky to have it replaced. Not sure where the cable is lined up on your car but try to trace it.
its not a hard thing to fix... dont worry man... !!! mine sometimes doesn't pop up as well... i usually insert something underneath the lever to keep it up so i can walk to the tank cover and open it manually... but it only happens to me sometimes...
I believe there is a spring on the cap itself. Sometimes, u just need to bent it a little just like what I did for my car. Or spend RM 10 for a used cap from the chop shop. Evo maybe a little expensive.
A set of RX7 FD single plate clutch for sale....came with aftermarket lighten flywheel(Brand not sure).... condition of the clutch plate and cover is still quite new as you can see in the picture....