Hi Vinicius, what are you using for your new tab page? That particular option only works with the built-in Firefox new tab page. It doesn't work if you change your new tab page to a blank page or use an add-on to replace it. There is a bug on file to find a way to show it in those additional scenarios, but the developers do not want to trigger it at the wrong time (for example, when a page opens a blank frame to render part of its content) which would create a very random experience. If you prefer a blank page, you can switch to using the built-in page and disable all of the categories of content that Firefox displays on the page. More info on those settings in this article: [[Customize your New Tab page to hide or display content]]. I think there will still be a gear icon in the corner.