In the 2019 version of Unity3D, there is an option under Project Settings → Player → Virtual Reality Supported → Stereo Display (non head-mounted) to set up the use of a 3D stereoscopic display (for example, using a 3D monitor and NV 3D vision kit). However, I cannot find this option anymore in the 2020 and 2021 versions with installed "XR Plugin Management".
QUESTION:
How can I use this option in the 2020 and 2021 versions?
There is a couple of ways to resolve this situation. Sadly for 2020+ versions, Xr plugin has depreciated the previous way to do it, unity now relies on the external vendors and plugin developers to implement their own versions of stereoscopic rendering.
However, this effect can be achieved by a simple custom script where the main camera is moved a specific amount corresponding to the IPD and on a specific frequency corresponding to the refresh rate.
This methodology will not work towards head tracking since object fixation and pivoting would need to be implemented through APIs