Ah shoot I suppose I forgot to update that part of the docs, sorry!
I combined all of STM's regular shaders with the SDF shaders, just check "SDF Mode" in the material settings to use that! So the shader you want is "Unlit Outline", and then enable SDF mode on the material.
Still no updates on the outline shader with URP besides this script: https://pastebin.com/wWv49mgG I'm really sorry about that, developing it has been a total roadblock for me no matter what direction I've tried to approach it from. I'll do some more brainstorming, because I would really like this to work finally.