Unifi Controller Hotspot (Add Email Address)

I need the Unifi hotspot portal customising so that it collects the customer email address and sends it to Stripe along with the other payment details when a customer signs up. They provide the ability to customise their template so I can provide the default files that I need the field adding to. Also, the Unifi Controller is free software so you are able to download it and run locally on your own machine, there is also plenty of documentation on their website and community. Stripe also requires 'tokenized' transactions which I don't think this does out of the box. For now I just want the email field and if quick and easy I would like the tokenized transaction facility added - may lead to more work as I would eventually like to build a full custom portal for my customers to select packages, logout devices and see their useage.