Thank you all for coming back to me. I have checked the wires and all are connected correctly. I am following the steps below
1. go into engineer mode via keypad 1
2.go to add bus option
3. go the keypad 2 and press A and tick which displays
B1 d52 t00, v3.11
4. At this point, from my understanding, this will assign the keypad. But no further progress , and keypad 1 still states, 'Press addr button etc.
5. I exit from engineer mode, key pad 1 is green, but keypad 2 still flashes red.
Any further help would be appreciated.