I am interested in speed running this game because I just picked myself up an nes classic and would like to know how to manually add time to livesplit

It's strange how they have this work but in Livesplit Layout Editor, click the + button and choose "Control", "Manual Game Time".

This sets it up for allowing you to manually add times.

Edit: Also once that is setup, you would want to right click the splits window, choose compare against, select "Game Time" instead of "Real Time".

Will do, thank you