Let me know if you have any other questions.
In order to redeem Microsoft 365 offer, you should visit samsung members app within the first 60 days of receiving the device then click on the M365 banner. In benefits. Then you will get one license key that can be used at Microsoft.com to sign up for the subscription.
Please check the following steps as well:
•Make sure that you are redeeming the offer from the same device.
•Signed in with Samsung account in Samsung Members.
•Account belongs to the same country.
•VPN is disabled.
•Make sure SIM is inserted.
Also, you may try to contact us through our support channels for further assistance if the issue persists, please visit the website via the below link, go to Support, then Contact, and we will assist you further with your inquiry.