To change the URL of any payment page, follow the below steps:
Select Charge from the menu on the left side of your screen
Click the Actions button on the page you would like to update
Click Edit
On the General settings page you can select to edit the "path" which is what we call the URL or address for your payment page. You can edit the way the text displays at the end of your page.
Keep in mind anywhere that you have linked to your payment page will need to be updated with the new URL.