I tried to order iTunes card but it’s not working

Your phrasing of the question leaves room for a lot of interpretation as to what "not working" means exactly.

Make sure it didn't get directed to junk mail.

Click on this link to find out how to 'Resend iTunes Gifts' --> https://support.apple.com/HT201783#resend - "If you sent an iTunes Gift and your recipient can't find the link to redeem it, you can resend them the gift from your iPhone, iPad, or iPod touch or your computer. When you resend an iTunes Gift, the recipient will receive another email with a link to redeem the gift."