Click on the link and apply for a card. This card is primarily for international students or anyone who doesn't have an SSN since they don't require it, but anyone can apply. Only needs approval. No purchase requirement. Statement credit will be earned upon first card usage. Valid indefinitely.
Click the referral link, apply for any card, and make a purchase in the first 3 months of opening the account. Valid only for new Discover cardmembers and must be approved by Dec 31, 2022.