I was told you can use them at the time of purchase towards the galaxy buds, or you can use them afterwards, after receiving the $200 in your email. I received mine after mentioning on this site, that it wasn't received.
Congratulations on your new S20 Ultra device! To redeem your $200 credit:
Download Samsung Shop > Register your new device > After this you will receive your credit within 4-6 weeks > Your credit will appear in Samsung Shop App
*Reminder: This credit is only applicable to certain products*
Lastly, after registering your device you can check your credit status at:
Hope this helps & have a wonderful day!
Hi you would need to go to your Samsung Shop app. In the left hand corner you would then scroll to my inbox and in there ,theres should be a space to register for your $200 credit. When you are registering they are going to ask for your purchase receipt and when you did the preorder and imei of the phone. After you input all the information you send the request. You should give it some because it will go under review. After the review is completed then you will get an email containing your $200 credit.