To embed a site into your formative, you can either:
Choose the embed content option:
Or click the "+" icon within a question, and select "Embed":
How to embed Genially presentations:
Go to https://www.genial.ly/en and sign up / log in
Choose a format and a template to create new content
Click "All Set!" at the top right to publish the presentation
Choose "Share" after publishing
Choose the "</> Insert" tab and copy the iframe code:
6. Paste the code into the Embed field in your formative!
5. (You may need to edit the width="xx" height="xx" part of the code so that the Genially displays well on your student devices.)