Illegal Invocation while passing data attribute on Ajax

I am trying to get the data attribute of a button with id delete_btn and send it through ajax. As a result, I am getting the following error.

Uncaught TypeError: Illegal invocation

JQuery

var id = $( "#delete_btn").attr('data-identifier');

$.ajax({

    dataType: "json",
    url: apiURL,
    data: { 'req': 'delete', 'id': id},

    success: function(data){
        //   do something

    },
    error: function (textStatus){
        //do something
    }

});

I have even tried getting the attribute value by

 $( "#delete_btn" ).data( "identifier")

But got the same error

via Chebli Mohamed