This question is similar to https://forum.u-blox.com/index.php/24146/c099-f9p-default-configuration-for-rover-and-base
but more specific.
I have two C099-F9P demo boards and want to set them up as base and rover. The C099-F9P User guide explains the rover setup and the first steps for base setup (section 6.1.2). That is fine. Then in section 6.1.3 it says:
'With u-center V18.06 or later connect to the C099-F9P using the dedicated ZED-F9 USB connection. See section 3.5.2 – “Required configuration of the base and rover” in the ZED-F9P Integration Manual  for details on configuring the required RTCM3 messages and setting the ZED-F9P as a reference station.'
where the reference  is ZED-F9P Integration Manual, Doc No. UBX-18010802. However in that manual (rev 3), section 3.5.2 is called 'Navigation epochs' which is not correct. The same manual does have a section '3.1 Receiver configuration' which is more relevant but I can't find any instructions for any remaining setup steps.
I did connect to the ZED-F9P using u-center and opened a 'Messages' window. It shows several NMEA messages highlighted but the RTCM3 messages are grayed out, including RTCM3 1005 Stationary RTK reference station ARP, which I think I need to activate.
Any help is appreciated.