Retrieving serialize form data sent by jquery ajax in WordPress

Actually i am trying to fetch form serialize data in php but i do not understand how to do it.

Here is my jquery ajax request code –
https://gyazo.com/e4fd850c587c84b86e75573eec2acd38

Here is serialize data –
https://gyazo.com/0cf0b477c2f2377c000d71d0fbac8923

Now how to get it using $_POST method in php file?

Thanks in advance!