To test your Shopify Payments setup, enable the test mode and use test credit cards to simulate payments.
Try below Credit card for test payment
Name on card Bogus Gateway
Credit card number
Enter each of these in turn to simulate different types of transaction:
1 to simulate a successful transaction
2 to simulate a failed transaction
3 to simulate an exception (this generates a message indicating that an error has occurred with the provider)
Enter any 3-digit number (for example, 111.)
Expiry Date Enter any date in the future.