Getting started help with Kamailio + Freeswitch

I've been running Freeswitch standalone for many years. So many years that I've largely forgotten how to set it up! However, following a DOS attack, I think it's time to put a Kamailio front end on. I've installed it on a separate host and managed to get to the point where I can get a SIP client to REGISTER, but when it comes to placing a call, there's a problem somewhere in the routing. So this project will be initially a bit of troubleshooting, probably using Google Meet where I drive the connection to my server and you tell me where I've gone wrong! I'm in the UK, but available outside normal office hours. This is quite urgent! If it goes well, there may be other follow-on projects. Cheers!