Adding Image texture filepath & ColorRamp into a Python Rig UI

Hello. Does anybody know how to add Filepath into a python Rig UI? Here’s an example.
So basically, I have a material with an Image Texture node. And I want to add a way to easily change the texture without having to go all the way to the Materials tab by implementing it to the Rig UI.

I also have a ColorRamp node that I also want to add to the Rig UI if possible.

set the SubType attribute on your StringProperty to FILEPATH