You should check the level of the transmission oil with the engine at standstill but while it is still warm.
Park the vehicle on level ground and keep it vertical (not on its side stand).Remove the cap at the top (1) and the screw on the right-hand side (2).
The correct level is determined by the screw (2).
If no transmission oil drips out of the latter then you will need to top up the level through the cap (1).
If instead some oil does drip out, this means there is plenty of oil inside and you should wait until the oil stops dripping out and reaches the level of the hole.