John Sauce
If it's already been verified that means that you used that phone number on a different cashwalk account. It could also mean that if you used a different number to redeem a gift card before this one, you would have to use that same number, but I'm not sure you might be able to use multiple numbers that aren't verified to another account to redeem a gift card. If this is the case you could make a TextNow account and get a free phone number to verify.