How can I claim my beats flex

Click here ➡️ https://www.apple.com/promo/pdf/EN_US_Apple_Music_Student_Promo_TandCs.pdf

• You will only become eligible for the free Beats Flex earphones upon making your first monthly payment for your Apple Music student subscription (i.e., you will not become eligible during your free trial). If you cancel your subscription during your free offer period, you will not be eligible for this offer.
• Within 30 days after you have become eligible, Apple will email you instructions for redeeming your free pair of Beats Flex earphones. Within 90 days of receiving this email, you must successfully follow these instructions to receive your earphones. You may be given the option to redeem earphones in various colors. If the color you order is not in stock, Apple will send you available earphones in a color of its choosing. The earphones can be shipped to you only at a mailing address in the region in which you have subscribed to Apple Music student.

If those 3 months were the free trial, you need to wait until you get charged the first time.

As mentioned, you should receive an email with instructions. Only then can you redeem the earphones.

If you have already been charged for the Student Subscription, how long ago was it that you were charged for it the first time?

Then you should have received the email already. You will need to contact Apple support then to get an other chance at redemption or at least another email. click here ➜ Apple Support