You can create a page for the payment by adding a Payment widget in the Page Builder. You need to add the Payment widget to provide the Payment option to the portal users in the customer portal.
The portal users will get the “Payment” options (PayPal and/or Stripe) as you have configured in the Payment Integrations settings.
Now, Drag and drop the Payment widget to the page layout section.
You can configure the Payment widget by clicking on the edit icon.
Payment Title: Insert the text caption to be displayed as the title on the Payment page.
After configuring the payment widget, click on the Save button and Publish the page.