Using the Motor Control Workbench Monitor on custom board

Hello,

I am using a custom board and I would like to use the Motor Control Benchs Custom Monitor.

As far as I understand I have to activate serical communication and simply generate and flash my custom board.

My problem is that I can not connect to my custom board. I thought that this might be the case because I only use an ST-Link to connect to my board (so just 4 cables).

Can someone help me out? What am I doing wrong? Do I have to connect something different to the ST-Link adapter?