I presume you mean you want to do this, second text block:-
But ‘unable’ doesn't tell us very much 😢
Unable how? Can’t find it? Gives an error message? Appears to work, but devices other than the one you are doing it on stay logged in?
What is the purpose of you doing this? (I know there are several reasons, but it would be useful to know which one(s) in this particular case)
Are you trying to watch NOW on another device after watching on one and don’t have boost?
If so you need to do a clean exit of the stream by hitting back to get to the homepage. Switching off etc won’t do anything and you’ll be forced to wait around 10 minutes to start watching on another.