JS FormData Image Upload to PHP Image can not be uploaded

i want to upload an image over Ajax and PHP. To get the Image i use FormData. The Ajax call is working fine from my point of view, but in my PHP code I always get the Error

Fatal error Uncaught ValueError: Path cannot be empty in C:\xampp\htdocs\fitnesslaeufer-redesign\profile\includes\settings\profile-settings-update-image.php:43

Stack trace: #0 C:\xampp\htdocs\fitnesslaeufer-redesign\profile\includes\settings\profile-settings-update-image.php(43): getimagesize('')

#1 C:\xampp\htdocs\fitnesslaeufer-redesign\profile\includes\settings\profile-settings-update-image.php(2): update_user_image()

#2 {main} thrown in C:\xampp\htdocs\fitnesslaeufer-redesign\profile\includes\settings\profile-settings-update-image.php on line 43
"

when I want to get informations ($fileinfo) about the image that is uploaded.

I tried to find a solution in some Posts but nothing helped to solve my problem.

For the Background I know how to upload an Image with PHP and now I want to update my image upload to Ajax / JS so that I can use SweetAlert2.

PHP Code:

    if(isset($_GET['user_id'])) {
        $user_id = mysqli_real_escape_string($connection, $_GET['user_id']);
    }

    $get_user_information = $connection->prepare("SELECT user_id, user_username, user_logo FROM user WHERE user_id = ?");
    $get_user_information->bind_param("s", $user_id);
    $get_user_information->execute();
    $result = $get_user_information->get_result();
    $row = $result->fetch_assoc();

    $user_id = $row['user_id'];
    $user_username = $row['user_username'];
    $user_logo_old = $row['user_logo'];

    $get_user_information->close();
    
    if($user_id > 0) {
        $targetDir = "../assets/img/users/";
        $allowed_image_extensions = array("png","jpg","jpeg","PNG","JPG","JPEG");

        if(isset($_FILES['user_logo']) && !empty($_FILES['user_logo']['name'])) {

            $fileinfo = @getimagesize($_FILES['user_logo']['tmp_name']);
            $width = $fileinfo[0];
            $height = $fileinfo[1];

            $user_image = pathinfo($_FILES['user_logo']['name'], PATHINFO_EXTENSION);
            if(!in_array($user_image, $allowed_image_extensions)) {
                echo "extension";
                exit;
            } else if(($_FILES['user_logo']['size'] > 1048576)) {
                echo "large";
                exit;
            } else if($width > "500" || $height > "500") {
                echo "size";
                exit;
            } else {
                unlink("../assets/img/users/$user_logo_old");
                $user_logo_new = $user_id.$user_username;
            }

            move_uploaded_file($_FILES['user_logo']['tmp_name'], $targetDir.$user_logo_new.".".$user_image);

            $user_logo_path = $user_logo_new.".".$user_image;

            $update_user_informations = $connection->prepare("UPDATE user SET user_logo = ? WHERE user_id = ?");
            $update_user_informations->bind_param("ss", $user_logo_path, $user_id);
            $update_user_informations->execute();
            $update_user_informations->close();

            echo 1;
            exit;

        } else {
            $get_user_logo = $connection->prepare("SELECT user_logo FROM user WHERE user_id = ?");
            $get_user_logo->bind_param("s", $user_id);
            $get_user_logo->execute();
            $result = $get_user_logo->get_result();
            $row = $result->fetch_assoc();

            $user_logo_path = $row['user_logo'];

            $get_user_logo->close();

            $update_user_informations = $connection->prepare("UPDATE user SET user_logo = ? WHERE user_id = ?");
            $update_user_informations->bind_param("ss", $user_logo_path, $user_id);
            $update_user_informations->execute();
            $update_user_informations->close();
            
            echo 0;
            exit;
        }
        echo 0;
        exit;
    }

JS Code cutout:

....
const user_id = getCookie('user_id');

var formData = new FormData();
var file = $('#user_logo');
formData.append('file', file);

$.ajax({
   url: "../profile/includes/settings/profile-settings-update-image.php?user_id=" + user_id,
   method: "POST",
   data: formData,
   contentType: false,
   cache: false,
   processData:false,
   success: function(response) {
       if(response == 1) {
           Swal.fire({
             title: "Profile picture is changed!",
             type: "success",
             closeOnConfirm: true
           });
        } else {
           Swal.fire({
              title: "Something went wrong!",
              type: "error",
              closeOnConfirm: true
           });
        }
   }
})
....

source https://stackoverflow.com/questions/68975931/js-formdata-image-upload-to-php-image-can-not-be-uploaded