How to make the button not follow it when the camera moves in libgdx?

Question

libgdx

I have a button, I need it to be fixed, that is, if we move the camera around the map, the button remains in its original place. I tried using setProjectionMatrix(camera.combined), but the button does not have such a property. This is probably a very stupid question, but I recently started learning libgdx, I'm trying to slowly delve into it.