Get azimuth elevation of camera


I am working on experiments I designed a scene with 12 camera, I fetched each camera matrix (4x4) then I tried to use it in pytorch3d yet result was not good all camera location was wrong ( I think the reason the coordinate system). I found pytorch3d support look_at function which take argument [azimuth - elevation -distance] and return both Rotation and Translation.

My question How I get azimuth and elevation for camera ?.