Did you follow the links for the Playstore voucher to claim the offer @Pleco
Check out the small print please of the offer as this will hold the claim start and end dates and provide the timeframe to get the offer.
https://20203.samsungpromotions.claims/googleplay/en-GB holds more information.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.