Glizzy Guzzler Overdrive

Saw multiple get additional .10¢ off for Halloween coupons then would click notification, app opens and saying invalid. Check coupons tab, nothing appears. This is pretty constant and not sure if it’s becuase it’s not available in my area (Sinclair, WY to SE Wyoming) but would be nice to have a fully functional app. Additionally the signage at the stations declare .20¢ off if using mobile advantage however only give .15¢ I’m open for explanations.