NO.. this is amex normal validation procedure, will strongly suggest DONT use this for running offer for brands page, due i) multiplier points credit may take time ii) have to be careful , cookie requirement (have to record video for future escalation etc etc) etc etc...You need to enter card number and agree to tnc before making the purchase. So enrollment is required. You cannot simply visit the website and make the purchase. It is like making purchase at eligible merchants landing from Amex website offer page and then make the purchase.
instead, use voucher reward multiplier , reward will be posted within 2-3 days including multiplier.. no tensions. the sms you receive for otp/ confirmation itself contain multiplier word in it.