Esp 3 needs to be a client only as far as I understand your description. Yes, it should send a GET or POST to esp 1 (does not matter which, I think).
You should post your updated esp 1 sketch here because it has been significantly altered. I remember it is quite long, so you may not be able to post it in code tags. I also remember quite a lot of repetitive code, so perhaps we can suggest some ways to shrink it.