If you fall into this following category then you can still claim, you have 60 days from the day you purchase to submit a claim...
*Purchase a qualifying S21 phone from a participating retailer between 1st - 30th September, 2021 to claim a free pair of Galaxy Buds Pro and a Galaxy SmartTag. Claims must be submitted within 60 days of the purchase date. Full Ts&Cs apply.
(From the Samsung Promotions webpage)