Hey thank you for making a build for Unreal 5.0. This is super useful for my FPS project.
#-#-#
Also a bit of advice for those who do not know where to get and place the freetrackclient64 dll. I was confused at first and eventually figured this out. 
Where to get freetrackclient64 dll
I downloaded and installed opentrack and got the freetrackclient64 out of the “modules” folder. I like OpenTrack because it is under the ISC license.
Where to put freetrackclient64dll
You want to put the freetrackclient64dll in the same folder as the freetrack.uplugin. DO NOT put it in freetrack/binaries folder otherwise it will not work and it will crash your engine when you try and start it up.