You can activate your cash app card using QR code or you can use it another way without QR code. But Still, If you are unable to activate your Cash Card, please contact the Cash App Customer Support and request assistance. These people will help you How To Activate Cash App Card by phone, so you can solve the problem in just a few minutes. However, you can visit our website. https://www.apple-supportphonenumber.com/blog/activate-cash-app-card