Signing in or out of Hulu on a device like the Roku can be a little different than signing in on your phone or computer. All you need to do is use your Roku remote and go to your profile settings in the Hulu app.
How to Sign Out of Hulu on Roku (How to Sign Out of Hulu on Roku)
First, open your Hulu app on the Roku. Then follow these steps to sign out of your Hulu account.
Select your profile icon on the Hulu main page.
Scroll down and select Logout.