How to add a texture to unlit shader graph in inspector?

I have made a unlit shader that maps a texture based on uv coordinates in the world space but in the inspector I cant chose the texture to be used with the shader. is there something I should be changing? Thanks152460-screen-shot-2020-02-06-at-110845-pm.png

For anyone who is looking for a solution, you need to just bring in a new texture2D node from the panel on the left hand side on the shader graph window and that will allow you to modify that parameter in the inspector.