FTDI232 and GNS FM9, what voltage
The FTDI232 IC has a pin called VCCIO that controls the levels of its IOs.

If it is connected to the 5V supply from ths USB port, then the TX signals will have a level of 5V and the RX signals will be 5V compatible.

If it is connected to the 3V3OUT pin of the IC, which is a 3.3V output from the integrated LDO, then the level of the TX signals will be 3.3V.

So, in your case, you have to select the 3.3V levels with the jumper on the board.

Note that if you choose the 5V levels, you will most probably fry the FM9, if this is indeed operating from 3.3V! So don't try it!