Radio control and esc's

I have a vx3 receiver wired to a uart port of an watercooled and waterproofFSESC75200 75V esc the receiver pairs to the remote but when I pull the trigger nothing happens can any one please help I dont know what to do to test any ideas

Maybe you mixed up the RX, TX wires? Try swapping them.

when you checked if Tx Rx is right, you should select in the VESC Tool menu App the UART App or PPM/UART