[SOLVED] building obs-websocket

So I'm trying to build obs-websocket: https://github.com/Palakis/obs-websocket/releases I'm using Alien Bob's version of OBS (27.0.1.)

I have the websocket source and obs source unpacked to ~/src/obs/*

Instructions say: "On other linux OS's, use this cmake command instead:
cmake -DLIBOBS_INCLUDE_DIR="<path to the libobs sub-folder in obs-studio's source code>" -DCMAKE_INSTALL_PREFIX=/usr .."

Here's what happens when I try to build it:

% ~/src/obs/obs-websocket-4.9.1/build cmake -DLIBOBS_INCLUDE_DIR="/home/hildegard/src/obs/obs-studio-27.0.1/libobs/" -DCMAKE_INSTALL_PREFIX=/usr ..
-- Configuring done
-- Generating done
-- Build files have been written to: /home/hildegard/src/obs/obs-websocket-4.9.1/build
% ~/src/obs/obs-websocket-4.9.1/build make
[ 3%] Automatic MOC and UIC for target obs-websocket
[ 3%] Built target obs-websocket_autogen
[ 6%] Building CXX object CMakeFiles/obs-websocket.dir/obs-websocket_autogen/mocs_compilation.cpp.o
In file included from /home/hildegard/src/obs/obs-websocket-4.9.1/build/obs-websocket_autogen/UVLADIE3JM/../../../src/WSEvents.h:30,
from /home/hildegard/src/obs/obs-websocket-4.9.1/build/obs-websocket_autogen/UVLADIE3JM/moc_WSEvents.cpp:10,
from /home/hildegard/src/obs/obs-websocket-4.9.1/build/obs-websocket_autogen/mocs_compilation.cpp:2:
/home/hildegard/src/obs/obs-websocket-4.9.1/build/obs-websocket_autogen/UVLADIE3JM/../../../src/WSServer.h:29:10: fatal error: websocketpp/config/asio_no_tls.hpp: No such file or directory
29 | #include <websocketpp/config/asio_no_tls.hpp>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [CMakeFiles/obs-websocket.dir/build.make:76: CMakeFiles/obs-websocket.dir/obs-websocket_autogen/mocs_compilation.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:84: CMakeFiles/obs-websocket.dir/all] Error 2
make: *** [Makefile:136: all] Error 2
% ~/src/obs/obs-websocket-4.9.1/build

Anyone gotten this one to build?