Screen timeout

I have been trying to learn this ad old app and all that it has to offer so I'm doing a lot of reading going from one screen to another and yes I take too long it makes me sign in again in other words it will log me out and make me sign in again and it is very frustrating when I've got to continuously love back in how do I fix this to not log me out so quickly. So my question and desperately need an answer. / need more screen time adjustment how do I set it for a longer time.

Truly getting upset because learning this is not an easy task.

Weary

Coe Cronin