I've been trying to follow the instructions under "Develop>Oculus documentation>Unity>Get Started" on Unity 2019.4.4f1, but while the app works fine in the editor preview, when I start it from "Unknown sources" on the Quest, I invariably see only a black void. I can interact with the guardian fine. If I put the HMD to sleep and wake it up again, I briefly see a flash of the standard Unity sky and ground scene before the void shuts everything out. I've tried recreating a project from scratch and I get the same phenomenon out of the box. I initially had not created an XRRig in the hierarchy, but doing so (and deleting the old main camera) has had no effect.
I also tried replacing the XRRig with an OVRCameraRig, but that changed nothing.
Is there a tutorial for developing for the Quest on Unity 2019.4 (that works)?