How do you use materials on imported FBX files?

I'm trying to use some purchased Unity materials on imported fbx files, but for some reason it doesn't seem to work and Google doesn't seem to have an answer
The full situation is that I have Clayxels, which is a tool to created 3D objects. Objects from here can be exported as fbx using the fbx Exporter tool. It also has a freeze object, which looks like it's pretty much doing the same as exporting and reimporting the fbx files

In the below screenshot I have two objects using the exact same material. There's the standard cube object and then there's my imported fbx file. The inspector looks the same for both, with the exception of the used mesh
Is it impossible to use fbx files with materials? Or is there something I need to do first?
I'm using URP. I don't know if that makes a difference