When you cancel the subscription, after your final billing cycle ends, HP Instant Ink cartridges no longer work and should be mailed back to HP in a recycling envelope. You can continue printing by using regular HP cartridges from the store or re-enrolling your printer in HP Instant Ink. Keep in mind that Instant Ink is an alternative way to print, where you are shipped ink before you need it as a part of a monthly service, not a method of purchasing and owning cartridges.
Hope this helps!
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!