I have tried but not working.
To increase session to time for Admin :
Stores -> Configuration -> Advanced -> Admin -> Security -> Admin Session Lifetime (it must be in seconds).
Uncheckd uses System value option and add your value in the textbox.
The Minimumm second is 60 and the Maximum is 31536000 (for one year).
Refer below screenshot for more details. Can you please help how to increase session log out time.