Unifi captive portal help


We’re a restaurant with a Guest WiFi network managed by a Unifi controler.
Unifi allows us to make a captive portal, that’s what you get when you want WiFi in an airport, i.e. you connect to the Guest network and get a Web page telling your to enter your email address to get Internet access (and you’re already understanding where I want to go…).
I’d like this portal page to be a Mautic form so that my customers have to give their email address to my Mautic.
My Mautic is not on the LAN managed by the Unifi router.

Here are some links to how it works on the Unifi router :

Did anybody succeed in doing that ? Or has idea on how to do it.
As you can read on these pages you can use Facebook or Google authentication, I don’t need authentication I just want customers to give their email to my Mautic before getting access to the Net.

I’m not really answering but I think I found a lead but still need help.

The fact is Unifi network portal page uses a form with a ‘Connect’ button and Mautic form has a ‘Submit’ button. I think I need a way to submit both form action with one button (one click).
Mutic form is :
<form autocomplete="false" role="form" method="post" action=" https://mautic.domain.com/form/submit?formId=3 " id="mauticform_wificredentials" data-mautic-form="wificredentials" enctype="multipart/form-data">

<button type="submit" name="mauticform[access_internet]" id="mauticform_input_wificredentials_access_internet" value="" class="mauticform-button btn btn-default">Access Internet</button>

<input type="hidden" name="mauticform[formId]" id="mauticform_wificredentials_id" value="3">

<input type="hidden" name="mauticform[return]" id="mauticform_wificredentials_return" value="">

<input type="hidden" name="mauticform[formName]" id="mauticform_wificredentials_name" value="wificredentials">

<input type="hidden" name="mauticform[mauticpage]" value="2" />


On the Unifi page the form looks like this :

<form name="input" method="post" action="login">

<input name="connect" type="submit" value="Connect" id="connect" class="button requires-tou" />


If anyone knows how to combine/merge these two html forms it would be appreciated.