code: function createIframe(config) {
      let { url, width, height, allow, callback, appendTo } = config;
      let iframe = document.createElement('iframe');
      let winWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
      iframe.className = 'vimeo-video gvideo';
      iframe.src = url;
  
      if (height) {
          if (isMobile && winWidth < 767) {
              iframe.style.height = ''
          } else {
              iframe.style.height = `${height}px`
          }
      }
      if (width) {
          iframe.style.width = `${width}px`
      }
      if (allow) {
          iframe.setAttribute('allow', allow)
      }
      iframe.onload = function() {
          addClass(iframe, 'iframe-ready');
          if (utils.isFunction(callback)) {
              callback()
          }
      };
  
      if (appendTo) {
          appendTo.appendChild(iframe);
      }
      return iframe;
  }
docs: Create an iframe element
  
  @param {string} url
  @param {numeric} width
  @param {numeric} height
  @param {function} callback