There is only one reason to Shank the ball (Hit the ball on the shank, or shaft/open face):
You rolled the club face open with your hands (on the backswing), and you did not get it back to square by impact!
Easy fix!… keep your hands out of the golf swing and let Large Muscles do the work. Or, keep the club face square the entire swing. Watch
[youtube https://www.youtube.com/watch?v=jAirSQJVbSE&w=425&h=349]