(NOOB QUESTION) How to make GameObjects into meshes?

Hey everyone. I was wondering if there is a way to transform a GameObject into its own mesh.

Example:
Say I use Probuilder to create some kind of unique object out of a cube. Is there anyway I can make said unique object into a mesh? (When I say mesh I mean into the category where Unity provides basic meshes like “Cube” “Sphere”, and “Cylinder”.) For some reason I can’t figure this out, and my online searches don’t seem to be digging up any answers. Maybe I’m not good at naming keywords…

Thanks for answers in advance!

The Mesh is accessible in the MeshFilter Component.

You’re welcome to take a look around my MakeGeo project which has tons of stuff related to procedurally generating various things in Unity.

MakeGeo is presently hosted at these locations:

https://bitbucket.org/kurtdekker/makegeo

https://github.com/kurtdekker/makegeo