How receive HTTP post from Infusionsoft

Hello, sorry for the question but I don’t know how to do, I have a membership site so to create a user i need to send the datas from the contact something like this:

https://mywebsite/index.php?/register/AXov48/?&firstname={Contact.FirstName}&lastname={Contact.LastName}&email={Contact.Email}

But I have a http post in a campaign, when a specific tag is added to a contact, start a sequences with a http post, and I don’t know if like my URL above is that I receive from Infusionsoft because any user is create in my membership site, and also I tried to send the HTTP post to my php file that contain this code and doesnt’ work, can you please help?:

<?php $contact_params = $_POST; $url= 'https://mywebsite/index.php?/register/AXYv48/'; foreach ($contact_params as $param=>$value){ $$contact_params[$param] = sanitize_text_field($value); } $user_email = $contact_params['email']; $first_name = $contact_params['firstname']; $last_name = $contact_params['lastname']; $finalurl = $url."?&firstname=".$first_name."&lastname=".$last_name."&email=".$user_email; echo $finalurl; echo "" ?>

Please any help?

In this post you are receiving with POST but your parameters are in the URL which is a GET method…right there it would break.