copy the bitPay invoice url from the bitPay page, like this
Paste the link in the input box above and click confirm to begin
The payment interface provides you with the amount in BTC, payment ID, and memo that shows the merchant.
Click on pay button, for card option: enter your email, phone number, for users not logged in, and make payments with card,
or choose from account this requires that you are logged in and payment will be made from your
On successful payment you will be notified via email, check your bitPay invoice page for funds recipient, this may take few mins.