How to paint a static mesh?

I don’t know where the problem is. I just want to pain a simple cube-shaped static mesh and I cant…

To paint a mesh you need to first create a material that has a Texture sample and Vertex Color nodes. Multiply the output channels from both these nodes and pass the product into the materials Base color node. Assign a texture file to the Texture sample node. Save go back into the level editor and assign this material to your static mesh.

Now go to the Paint tool select a vertex color of your choice and paint onto the static mesh with LMB. Make sure your mesh is selected in the world outliner panel.