Setting up a payment page is same as discussed in ‘How to create a HubSpot payment form’.  Let’s take a look at the process to set up the Authorize.net payments.
Open FormPay app.
Navigate and click on Gateways tab from the navigation panel on the left.
On the next page, there will be all payment gateways listed that are supported in the FormPay app.
[All Gateway screenshot]
Spot the Authorize.net gateway and click Setup on the right of it.
After this, fill the fields under Live Account Details asking for — Live Login ID, Live Transaction Key, and Live Client Key.
Once done with that, choose your currency.
Finally, click Activate Gateway.
You can always connect with our support team if you find any trouble setting up any gateway.