Can't read form values

Are you serious?

The error message says exactly what the problem is.
You are trying to insert an empty row. All the passed values are NULL

So the problem could be located somewhere around the AJAX call

I'm tracing everything or it's just I miss something. I tried using MODAL form it successfully inserted the values. But when I tried a simple form I got that error. I check the Database but its not the problem. I'm pointing the problem when the TIME i clicked the button calling the save function.

In my own understanding the URL is correct. calling on the function.