flat shader with transparency

Hello,
I am trying to have a shader with a flat color but with transparency.
I tried ti use the particle shader for this but its rendering the blackfaces which is not what I want.
I just need a solid color everywhere in the mesh but with transparency.
Is there a way to achieve this?

Has been discussed a lot. I think XRIT also has a shader that can work with this

Thanks for the info, but that’s for URP.
Is XRIT a shader kit? Would you have a link?

I’m not familiar with built in shaders, but there are probably shaders available.
XRIT is XR Interaction Toolkit, but it has some shaders