I am trying to work out the best system for our invoicing and payments.
Currently we use Xero to invoice a customer.
In Xero, you can add different payments through their store such as Stripe, Square, etc.
These can then be easily added to an invoice using merge tags so when the customer clicks on the link, it goes directly to a payment side.

We do not want to use any of the available systems for a variety of reasons.
We want customers to be able to make a payment through a Westpac Payway Trusted Frame.
At the moment, you can set up a custom payment option that allows you to add a URL.
Currently the URL will take you to a payment page on our site with the Westpac Trusted Frame. However, none of the information from the invoice comes across, meaning the customer would then have to manually add in the price of the invoice and invoice number into some input fields which is not ideal as it is prone to user error.

Ideally when the customer clicks on the custom payment option, it would pass over some parameters into the url. For example: url?amount=invoiceamount&number=invoicenumber

Is this at all possible?

I’ve been searching the forums and documentation but have so far come up with nothing.