Trouble to find the Oil level plug

[Tomas22]

Hello,
I'm having trouble finding the gearbox oil level plug. After replacing a driveshaft, the gearbox oil leaked out, so I refilled it with fresh oil. However, I want to make sure I haven't overfilled it.
I've attached a photo, but I don't think this is the correct plug. I found the drain plug at the bottom of the gearbox, and it takes an 8 mm tool. I also found a plug above the driveshaft that requires a 30 mm socket, but I assume this is not the oil level plug.
Does anyone know where the gearbox oil level plug is located?
The vehicle is a 2018 Citroen C3 Aircross 1.2 PureTech with a 5-speed manual gearbox.
Thanks in advance for your help.

[PaulC5]

I think the Citroens we have owned did not have oil level plugs on the gear boxes. I did not need to fill any of them up but to get the level right would involve draining and filling with the correct amount. However, this does not mean all Citroens do not have one.