Uncaught Error: Failed to find: -lhs-rhs-canvas

[flatmax]

I'm getting around shadow dom in litelement like so :

  render() {
    const div = document.createElement('div');
    div.style.height = '100'
    div.style.width = '300'
    document.body.appendChild(div);
    const doc = new window.Mergely(div, { lhs: this.codeText, rhs: this.codeOrigText });
    
    return html`... other stuff`
  }

However when I run, I get the following bug :

mergely.js:12189 Uncaught Error: Failed to find: -lhs-rhs-canvas

[wickedest]

Try giving the DOM element an id.