Connect Raspberry Pi 3B+ to Pixhawk 4 through from serial USB FTDI to TELEM 2 port


Trying to run the vehicle_state example code from dronekit on a Raspberry Pi 3B+ connected to a Pixhawk 4 from USB to TELEM2 port. I configured the TELEM2 port for serial as described at the end of this page
I’m using a FTDI cable linked here

I’m using the connection string = “/dev/ttyUSB0” with a baud rate of
57600 and I get the following output on terminal: WARNING: dronekit: Link timeout, no heartbeat for last 5 seconds. The connection string with ACM0 or AMA0 doesn’t work either.
Tried a separate serial check code here but gives gibberish with each baud rate.

Not sure where I’m going wrong. Whether it’s the connection string, baud rate or the hardware connection?