If the order payment has failed, there could be several reasons for that - let's go over the recommended troubleshooting steps.
Use the "Retry" button
Click on the "Retry" button next to the order - most likely, the payment will go through this time.
Check if a payment method (or balance) has been added
Navigate to the Payments section of your Printify account to check.
How do I set up payments in Printify?
Check if there are enough funds available on the card (or in the balance)
If you're positive that a card has been added to your Printify account, check whether there are enough funds available. If so - you may want to try using an alternate credit/debit card or contact your bank to determine why the payment is being declined.