javascript - Ajax: How to pass both form data and credentials on submit?

Main Problem :- Ajax: How to pass both form data and credentials on submit?

I have the below function which is called when a user clicks on a submit button:

<script type="text/javascript">
function submitForm() {
    console.log("submit event");
    var fd = new FormData(document.getElementById("campaign_form"));
    console.log(fd);
    var username = $('#username').val();
    console.log(username);
    var password = $('#password').val();
    console.log(password);
    $.ajax({
        type: "POST",
        url: "http://localhost/testing/post_campaigns.php",
        data: fd,
        data: {
            "username": $('#username').val(), 
            "password": $('#password').val()
        },
    });
    return false;
}
</script>

My php URL is called properly, but I don't see that my data is passed.

For example, I would typically expect to see in developer tools:

http://localhost/testing/post_campaigns.php?username=XXX&password=YYY

But I only see:

http://localhost/testing/post_campaigns.php

My variables are written to the console properly so I know they exist and have values.

I'm sure the issue is along the lines of my syntax; but I'm not sure how to format my Ajax properly to accommodate both object FormData and string variables username/password.

Basically, my overall code asks the user for a sheet they have filled out with specific values under designated column headers, and I read that information and POST it to our ad server. So I need both the FormData and the Username/Password provided by the user to be passed to my PHP file when I execute the POST request to our ad server with the information/changes requested by the user.

If my question/dilemma is not clear or you need more code, please let me know.

Thank you,

Edit: Attaching a screenshot of FormData in console per request.

Solution:

jQuery / AJAX Code:- For Sending formdata with other javascript variable together.

<script>
    $('#btn').on("click", function () {
            var formData = new FormData($("#form1")[0]);
            formData.append('ipid',id); //id is the variable that has the data that I need
            var path = "http://localhost/testing/post_campaigns.php",
            $.ajax({
                url: path,
                type: "POST",
                data: formData,
                contentType: false,
                processData: false,
                success: function (stuff) {
                    $("#resp").html(stuff);
                }
            });
        });
    });
</script>

formData.append("param", "value");

 echo   $pid = ($_POST['ipid']);

https://developer.mozilla.org/en-US/docs/Web/API/FormData/append