Unable to open file stream for given path error with MSGraph SDK

Question

I have a web app I wrote in JS. There is a form that allows file upload, which is then handled by PHP.

I have an account already, and I've registered an application under MS Azure and set the following permissions:

Files.Read
Files.ReadWrite
Files.ReadWrite.All
Sites.ReadWrite.All
User.Read
User.ReadWrite

Here is the code I use:

use Microsoft\Graph\Graph;
use Microsoft\Graph\Model;


if(isset($_FILES)){


    $end_result = new return_object();

    $message = "stock msg";
    $row_error_object_array = array();
    $overall_error_array = array();
    $general_message = "stock general msg.";
    $success = true;

    $temp_file_name = $_FILES['file']['tmp_name'];
    $original_file_name = $_FILES['file']['name'];
    
    $company_id = $_POST['company_id'];

    // Find file extention
    $ext = explode ('.', $original_file_name);
    $ext = $ext [count ($ext) - 1];

    $new_file_name = $original_file_name;

    // Remove the extention from the original file name
    $file_name = str_replace ($ext, '', $original_file_name);
    // $new_name = 'videos/'.$file_name . $ext;

    $path_prefix = "files/$company_id";

    if(!is_dir($path_prefix)){
        mkdir($path_prefix, 0750, true);
    }

    // $new_name = $path_prefix . "/" . $new_file_name . date("Y-m-d h:i:sa") . $ext;
    $new_name = $path_prefix . "/" . $file_name . date("Y-m-d h-i-sa") . "." . $ext;


    // $new_name = $new_file_name;

    if (move_uploaded_file ($temp_file_name, $new_name)) {

        // echo "we moved the file!<br>\n";

        $general_message = $general_message . "File Move Success.";

        $file_name = $_FILES["file"]["name"];
        $file_type = $_FILES["file"]["type"];
        $file_size = round($_FILES["file"]["size"] / 1024, 2) . "  Kilo Bytes";

        $general_message = $general_message . "Trying to upload.";        

        $guzzle = new \GuzzleHttp\Client();

        $tenantId = 'my_tenant_id';
        $clientId = 'my_client_id';
        $clientSecret = 'my_client_secret';
        
        $url = 'https://login.microsoftonline.com/' . $tenantId . '/oauth2/token';

        $user_token = json_decode($guzzle->post($url, [
            'form_params' => [
                'client_id' => $clientId,
                'client_secret' => $clientSecret,
                'resource' => 'https://graph.microsoft.com/',
                'grant_type' => 'client_credentials',
            ],
        ])->getBody()->getContents());
        
        $user_accessToken = $user_token->access_token;

        $general_message = $general_message . "Creating new Graph.";

        $graph = new Graph();
        $graph->setAccessToken($user_accessToken);

        $graph->createRequest("PUT", "/me/drive/root/children/".$_FILES["file"]["name"]."/content")
              ->upload($_FILES["file"]["tmp_name"]);

        // $graph->createRequest("PUT", "/me/drive/root:/".$_FILES["file"]["name"]."/content")
        //       ->upload($_FILES["file"]["tmp_name"]);

        $general_message = $general_message . "File uploaded!
        
    } 
    else {
        // $error  = $_FILES["file"]["error"];
        // $response = array('success' => false, 'msg' => $error);
        // echo json_encode($response);
        $success = FALSE;
        $message = "Fail - File wasn't moved.";
        $general_message = "Fail - File wasn't moved.";

    }

    $end_result->success = $success;
    $end_result->message = $message;
    $end_result->row_error_object_array = array();
    $end_result->overall_error_array = array();
    $end_result->general_message = $general_message;

    print_r(json_encode($end_result));

}
else{
    $end_result = new end_result_upload_employee_info();

    $end_result->success = true;
    $end_result->message = "No file!";
    $end_result->row_error_object_array = array();
    $end_result->overall_error_array = array();
    $end_result->general_message = "NO FILE!!!!";

    print_r(json_encode($end_result));
}

Basically I'm moving the file to the server's file structure first, and then try to upload it in OneDrive. I plan to remove the part of saving to the server first when I get the OneDrive upload to work.

Right now I'm stonewalled and I'm not sure how to proceed. I also attempted this answer, but I'm getting an "interaction_required" error from Guzzle.

As much as possible, I want the upload to be fully automated, one where the user won't be required to log in, in order to make the user experience as seamless as possible.