HTML Form Post URL

Ok so I have a HTML form which is using javascript to display an image thats uploaded here is my HTML code

<form action="/inc/sendtochan.php" method="post">
              <label for="fname">Title:</label><br>
              <input type="text" id="fname" name="title" value="" size="64"><br>
              <label for="discription">Enter content description:</label><br>
              <textarea name="discription" rows="10" cols="60"></textarea><br>
              <label for="link">Link to content:</label><br>
              <input type="text" id="lcontent" name="lcontent" value="" size="64"><br>
              <label for="link">Select Image:</label><br>
              <div class="profile-picture">
              <h1 class="upload-icon">
                <i class="fa fa-plus fa-2x" aria-hidden="true"></i>
              </h1>
              <input
                class="file-uploader"
                type="file"
                onchange="upload()"
                accept="image/*"
                name ="imageurl"
              />
              </div><br><br>
              <input type="submit" name="submitcontent" value="Send Content to Channel">
            </form>

The javascript involved which displays a box, which then changes to a preview of the image selected

function upload() {
  const fileUploadInput = document.querySelector('.file-uploader');

  if (!fileUploadInput.value) {
    return;
  }

  const image = fileUploadInput.files[0];

  if (!image.type.includes('image')) {
    return alert('Sorry Only images are allowed!');
  }

  if (image.size > 10_000_000) {
    return alert('Maximum upload size is 10MB!');
  }
  
  const fileReader = new FileReader();
  fileReader.readAsDataURL(image);

  fileReader.onload = (fileReaderEvent) => {
    const profilePicture = document.querySelector('.profile-picture');
    profilePicture.style.backgroundImage = `url(${fileReaderEvent.target.result})`;
    
  }
}

Everything works perfect and the image displays, now to the php from the post request, what I am trying to get is the url of the image to be posted, in my /inc/sendtochan.php I am reading the data from the post request with

$imageurl = trim($_POST['imageurl']);

But when I echo this, it basically is just returning the image name, what I want the post form to actually post is the image url. Any help would be appricated.

Thank you

I can get the image url to display straight away when its selected by adding this to the javascript

return alert(`url(${fileReaderEvent.target.result})`);

So I just need to actually have that url sent with the post request, now the image name