The parking at Keystone is not reservation based.
HONK partners with park Keystone for long term permits/seasonal permits and day/overnight parking only.
You can purchase the season pass here: https://parking.honkmobile.com/monthly/zones/57171
Or by searching in the HONK app for zone 57171 and choosing long term.
For the day parking, you must arrive and then pay upon securing your spot - no prepaying and spots are not reservable.
If you need help paying for parking at Keystone please contact HONK support or Park Keystone directly info@parkkeystone.com