You may get into the PBU Settings by using a keyboard and pressing the 'S' key. This may be done with a physical keyboard or the on-screen keyboard (view our guide here for pulling up the on-screen keyboard).
ALTERNATELY - You may open PBU and then triple-touch the bottom right-hand corner of the PBU screen to open the Settings.
If you wish to set a password to get into Settings you may do so from the Preferences tab as shown below. KEEP TRACK OF THIS PASSWORD or you will be unable to access settings.