How to compile shared open3d library with webrtc supported?

[ltaini]

Checklist

• I have searched for similar issues.
• For Python issues, I have tested with the latest development wheel.
• I have checked the release documentation and the latest documentation (for main branch).

My Question

I want to get shared library with webrtc supported,i executed the following commands on windows :
cmake -DBUILD_SHARED_LIBS=on -DBUILD_WEBRTC_FROM_SOURCE=on ..
cmake --build . --config Release --parallel 12
but failed at end.
the command told me :No update step for ‘ext_webrtc' No path setp for 'ext_webrtc',...No build step for 'ext_webrtc'.
can someone tell me how to get dynamic library with webrtc?thank you.