If the offer is mentioned on the printer box, it gets auto-credited to your Instant Ink account, once you choose a plan and enroll.
Refer to this document to know how to enroll the printer in Instant Ink.
If it is not credited in 48hrs after enrollment, please send us a private message with your Instant Ink account details or you may also respond to the private message I've sent out and I'll help you out, accordingly. Check next to your profile name, you should see a little blue envelope, please click on it.
Hope this helps! Keep me posted.
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