Why my purchase online gift card It's not ready yet supposed to be wait for only one hour and there will be delivery to the email that I provide but it’s been more than six hours and i still don’t have the gift card yet

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."