It's easy to redeem your Tidal card. You will only need to follow these instructions
Log into your Tidal account at www.http.tidal.com
Visit https://offer.tidal.com/voucher (or open your Settings and select Redeem).
Enter the redemption code and agree to the Tidal Subscription Terms.
Click the Redeem button to apply the gift subscription to the Tidal account you're signed into.