Hi @Polona Thanks for reaching out 😊
It's not possible to add a Youtube video to the item description page, but you could create a link in the description that opens up a page on your site with the video. You could also choose to open the page on Youtube directly.
Navigate to the Edit Item page, then add some text to the description box. Highlight the text you wish to link, then select the link icon. You will see a dropdown to link to an external page, with an option to open the page in a new tab. (I personally like doing this so that the site visitor does not lose their place on the page they were viewing.)
Note: If you are going to add the Youtube video to a page on your website you will want to create that first and publish the site so that you can copy/paste the correct URL in the link box.
