Go to Settings > Account > Average to Par > the handicap style will be Average to Par aka World Handicap System. You can adjust your Average to Par value and automatic settings here!
Turn the Auto Handicap setting to ON for Golfshot to automatically calculate an Average to Par. After turning Auto to On, Golfshot necessitates saving three 18 hole rounds in order to calculate you an automatic handicap. Turn this off if you wish to manually update your Average to Par.