No OPT In button for me
I do have a BMO Mastercard but it is not the one linked to my AM card.
This is what my offer looks like

Terms & Conditions
* Offer available to AIR MILES collectors with a linked Canadian- issued Mastercard (“Eligible Mastercard”). Offer valid Oct 18, 2024 – Oct 20, 2024, or while quantity of AIR MILES® Bonus Miles™ last at Dollarama stores in Canada. To be eligible for the offer, an eligible collector must first opt in to the offer by clicking the “opt in” button during the offer period. After opting in, an eligible collector can then earn 100 Bonus Miles when spending $30 at Dollarama in a single transaction and paying with an Eligible Mastercard during the offer period. Minimum qualifying purchase of $30 must be made in a single transaction on an Eligible Mastercard, and includes taxes, duty, eco fees, shipping and handling as applicable. For clarification, minimum qualified spend is calculated based on the entire purchase, being the total amount that is posted to the Eligible Card’s statement. Limit of one (1) offer per collector number. This offer can be combined with other offers. AIR MILES reserves the right to make changes to this offer and to terminate the offer at any time, for any reason and without notice. Your AIR MILES collector number must be linked to an Eligible Mastercard at the time of the eligible transaction. If you have a Canadian-issued Mastercard that is not linked to your AIR MILES collector number, you can manually link them by visiting airmilescardlink.ca and following the linking instructions. BMO AIR MILES credit cards are linked by default and do not need to be manually linked. Your Mastercard account must be in good standing at the time the Bonus Miles are awarded. To qualify for the offers, eligible purchase transactions charged to your Eligible Mastercard must be subsequently posted to your Mastercard account by October 20, 2024. In the case of an online purchase made during the offer period, it may not qualify if the Eligible Mastercard is charged on the shipping date and that date occurs after the offer ends. Mastercard is not responsible for the fulfillment of the offers. Purchases made by an authorized user per day of a supplementary card linked to the Eligible Mastercard do not qualify, unless the supplementary card is also linked to the AIR MILES collector number. Please allow up to 30 days after the unique offer’s end date for Bonus Miles to be posted to the collector account. Collectors who previously manually linked their AIR MILES collector number to their Eligible Mastercard and who no longer wish to participate in exclusive card-linked offers can unlink their Mastercard from their AIR MILES collector number at any time at
airmilescardlink.ca/unlink. The unlink feature is not available to collectors with a BMO AIR MILES credit card that was automatically linked to their AIR MILES collector number by BMO’s auto-link feature. ®™ Trademarks of AM Royalties Limited Partnership used under license by AIR MILES Loyalty Inc. and Dollarama. ™*/®* Mastercard is a registered trademark, and the circles design is a trademark of Mastercard International Incorporated. Used under license.