After you click "Buy Now", you will pay step by step as below:
STEP 2: When you click on "Pay with a Bank Account or Credit Card"
you will go to this page:
(When you have a PayPal account you skip "step 2")
After you complete payment,
you must click on the link "Return to Merchant"
You will be taken to a page to download product.
STEP 4: This is the page to download product:
Or Google Drive Store: