Local outline without postprocess on mobile issue

I have Tom Looman’s outline material but I’m unable to make it work on Oculus Quest with OpenGL ES3.1, it works fine in editor.
I wonder if some part of this material is unsupported on mobile.

It requires **Render Custom Depth **on the mesh, and **Custom Depth With Stencil Enabled **set in the project settings (which is in the post-process section, so surely I guess this is a post-process feature?)

Is there a way to fix it to work? Or some alternative solution I could look into?

Postprocess is a no go. For outline, you could try something some people refer to as reverse geometry. But I would attempt your needs with Fresnel-minus1and some mutliplier.
THis looks good Local Outline FX Without Post-Processing in Unreal Engine – Tom Looman