javascript_upload.js

function uploadFile (url, blob) {
  return fetch(url, {
    method:'POST',
     body: blob // also tried appending the blob to formData
  }).then(response => {
    if(response.ok){
      return response.json();
    } else {
      throw response;
    }
  });
}

onTakePhoto (dataUri) {
  const blob = toBlob(dataUri);
  this.uploadFile('/upload', blob);
}

UploadController.php

  public function blobUpload(Request $request){

    $pathresolver = new \FileUpload\PathResolver\Simple($_SERVER['DOCUMENT_ROOT'].env('temp_location'));
    $filesystem = new \FileUpload\FileSystem\Simple();
    $fileupload = new \FileUpload\FileUpload(file_get_contents('php://input'), $_SERVER); 
    $filenamegenerator = new \FileUpload\FileNameGenerator\Random(5);
    $fileupload->setPathResolver($pathresolver);
    $fileupload->setFileSystem($filesystem);
    $fileupload->setFileNameGenerator($filenamegenerator);
    list($files, $headers) = $fileupload->processAll();
    $fileName = $this->generateRandomString();
    return response()->json(env('SERVER_IP').'/temp/'.$fileName);
  }