Hi Les
As you are using this with your Joysway yacht you will not have an ESC with a BEC supply so just plug you battery into any of the sockets not used by the rudder servo and the winch servo.
Have you managed to contact the supplier re the missing box for the Radio
Dave

Hi Les, usually 1 and 3 are throttle and rudder, 2 and 4 are right stick up and down, and left stick right and left, 5 should be a switch?? use that one. Remember if you ESC has a BEC function under no circumstances use a battery as well, if your lucky it just wont work, or the magic blue smoke will appear!! As RN said ANY or NONE

Mark

Hi Les, ANY or NONE!! 😲
1 With separate RX battery: any socket not needed for servo etc.
Disconnect any BEC supply from the ESC, the red wire!
2 it seems to expect a BEC supply from the ESC, so you don't then need a separate RX battery anyway!
All clear? Cheers Doug 😎