computer3wire.c BL5S210 RS232 Serial is Not working

I am using BL5S210 to replace Rabbit board that is not available any more.
I am trying to setup serial communication with this board from a PC using Serial (RS232) and it is not working.
I tried to run computer3wire.c program from samples. I followed all instructions in the program. It compiles but I can’t enter any chars on both stdio or terminal.
Are there any additional setting or jumpers on the board to make it communicate.

Does your PC have a DB9 serial port, or are you using a USB to DB9 serial adapter?

If you loopback the serial port of the PC (connect Tx to Rx on the DB9) or the Rabbit (connect pin 1 to pin 6 on J11), are you able to see entered characters echo back? Checking the PC side would confirm you’re opening the correct serial port.

Do you have the correct baud rate set on the Rabbit and PC? The sample defaults to 57600.

Did you configure the PC to not use any handshaking (no hardware or software handshaking)?