I am trying to follow this tutorial
I made it up to the point where I am supposed to enable the Legacy Options, but it may not have installed correctly. Is there something I’m missing? I’ve tried to install it manually.
I know OpenVR is deprecated. If that is the case what do I need to do to stop the error. Thanks
Use 2019.3
It’s not deprecated, it’s been removed (in 2020.1). 2019.3 is the last version to support the old OpenVR package. They are working on a new one, but it’s not ready yet. See this blog post for more details.
Official out of the box support is not there so in that sense, the official support is deprecated 
You will have to wait for an announcement from Valve on the OpenVR subject.
As it is now, all we have is a confirmation from Unity that Valve is “working on it” whatever that means for our future development strategy choices.
Hopefully, soon we will know whether we are going to get stuck to 2019.3 or forced to switch VR platforms, or engine altogether…