Hi Céline thanks for posting in the community - I'm happy to help! Unfortunately I'm not positive what you're referring to. Can you please link to the video or provide a screenshot of the tab in question? 

In case you're referring to the "Notes" tool within Lucidspark its location may have changed since the video's creation. Originally located in the upper right corner Notes are now located within the Primary Toolbar under Team Tools. 

If Notes are something you use frequently you can pin them to the main section of the toolbar by clicking on the thumbtack icon. I hope this helps! Please let me know if I've misunderstood or if you have additional questions.