Fabian, I have the STWC050LT-01 I got from Amazon https://www.amazon.com/dp/B09QKX4L5R?psc=1&ref=ppx_yo2ov_dt_b_product_details
I took one of the cables (2 came with it) and cut off one end and crimped on a header so I could use some jumpers to hook it up. I am using an ArduinoUNO to do my testing. Here you can see the inner 2 wires on the ribbon cable are the TX and RX wires.
One thing to note you can not have the arduino plugged in with the USB cable to program it at the same time you are trying to communicate with the LCD screen through the arduino.
Let me know if this helps.
David