How to ban a robot?

Question

PHP

Hello, I have a website in php. nginx server. Lately, an empty submitted form has arrived. All fields are empty. Or any spam. The hidden fields that are filled in by js to identify the visitor are also empty. Those. The "platform" from which the form is automatically submitted does not support js.
Please tell me:
1) How to determine the ip address of this robot? Maybe somewhere in the nginx logs the user agent and ip of all visitors are written?

Answer 1

Firstly, you receive an empty form, why don't you stupidly send this application to the back box right away, in extreme cases, nowhere? (do not rush, read to the end)
Secondly - why crawl into nginx and study the logs, if on the back as a whole it is considered the right tone to fix the IP requests through ? Thirdly, there is no point in sending empty data to the robot. No matter how no error pops up between the front and back, in the worst case, it is likely that someone groped for an injection and sits loosening it $_SERVER['REMOTE_ADDR']