Hi!
By the looks of things the error is in our wiring diagram in the tutorial. Are you using a regular Bela board?
If so the wire that comes from the button to the digital input should actually be connected to one pin above. Look for pin Digital 6 (Pd: 17)
on the interactive pin diagram in the IDE to see exactly where the correct pin is.
Apologies for this, we will update the wiring diagram shortly.