A queue category will appear on the Tubi Home screen, above the Most Popular category. To manage your queue please click on the following link, https://tubitv.com/account/history and tap on Queue.
If you are not signed in to Tubi on your web browser, you'll be directed to a sign in page.
If you're directed to a sign in page, please sign in. Afterward you can access your queue by either following the instructions provided above or by clicking on your name on the top right-corner of your screen then on Account Settings.
Below is an image of the Queue page on Tubi.