Infusionsoft POST to wordpress to change role

infsrole.php

<?php

/*
UNTESTED CODE BELOW

Infusionsoft triggers a POST request that sets user roles.
This function retrieves that request and processes the role change.

Be sure to enter your $internal_access_key below.
You may need to change the meta key "infusionsoft_contact_id". Consult your infusionsoft plugin documentation to find what that key is named (or search the wp_usermeta table in the database)

@see https://bbpress.org/forums/topic/infusionsoft-and-forum-role/
@see https://wpfusion.com/documentation/webhooks/infusionsoft-http-posts/
*/
function bbp_infsoft_hook_set_role() {
	// Config
	$internal_access_key = "ENTER_YOUR_ACCESS_KEY_HERE"; // Or use get_option() to load from the database.
	
	// Get data sent to us by Infusionsoft
	$infsoft_contact_id = stripslashes( $_POST['contactId'] );
	$remote_access_key = stripslashes( $_POST['access_key'] );
	$role = stripslashes( $_POST['bbp_role'] );
	
	// Verify that the infusion soft access key is what the server uses.
	// This is a security measure to ensure people can't just change their own role, unless they know the access key.
	if ( $internal_access_key !== $remote_access_key ) {
		wp_die('Invalid infusionsoft access key.');
		exit;
	}
	
	// We're confident this is a legit request, so now we just need to get the user.
	// If the wordpress user ID is stored in infusionsoft, you could send that as another parameter.
	// Otherwise we need to locate which user the "Infusionsoft Contact ID" is assigned to.
	$user_query = new WP_User_Query(array(
		'meta_query' => array(
			array(
				'key' => 'infusionsoft_contact_id', // IMPORTANT: Change this to the user meta key that has the infusionsoft ID.
				'value' => $infsoft_contact_id,
			)
		)
	));
	
	$results = $user_query->get_results();
	
	if ( empty($results) ) {
		// If you get this error, ensure that the meta key used in "user_query" is correct!
		wp_die('Invalid infusionsoft contact ID ('. esc_attr($infsoft_contact_id) .'). That user no longer exists on this website.');
		exit;
	}
	
	// Get the first user from our query. There should only be one.
	$user = $results[0];
	
	// Assign the user role with BBPress (from @robin-w)
	bbp_set_user_role( $user->ID, $role );
	
	// Send a 1 to the browser to indicate success, then exit.
	echo '1';
	exit;
}

// Only hook in if the request uses our custom action "bbp_action" = "set_role"
if ( isset($_POST['bbp_action']) && $_POST['bbp_action'] === 'set_role' ) {
	add_action( 'init', 'bbp_infsoft_hook_set_role' );
}