How do I get to an apps settings on S6 Edge Plus?

[AC Question]

I have installed Checkbook Free on my S6 Edge Plus and I cannot get to the settings to create a PIN. How do I get to the settings for the app? The settings button was in the lower left hand corner. That is now a shortcut button.

 

[sethyboy]

Holding down on the Recent Apps button will function as a menu button if there isn't one inside the app (which it appears there isn't.)