I Can't Add an Operator

If you can’t add any operators (i.e., the + Add operator option isn’t available), it means the textures are already being used in a material. This is actually a safety feature of the platform, designed to reduce errors that could occur when a single texture is used by multiple materials and editing that texture would unintentionally modify all of them.

In that case, you can simply copy the existing texture as follows:

And once you are done with your edits then in the material select your new revision like so:

asdf