Insert data from a form

Where does the form currently POST the name and address information to?

I haven't made the form yet but normally it would be to an email

Submitting to e-mail not ideal, can be done but involves adding e-mail parsing logic.
Might be better to use the approach outlined at...
https://www.codeandcourse.com/how-to-connect-html-form-to-mysql-database/

Just use Wordpress template and create your own form in PHPRunner that would save the data in the database.
Otherwise I don't even see how it is related to PHPRunner.

Because there's a boatload of existing forms of all types out there that can POST to PHP scripts that sanitize and insert data into databases that PHPRunner can then work with.
Also, wanted to show a safer example for inserting user-supplied data in to the database. The example below uses HTMLPurifier (http://htmlpurifier.org) to sanitize input, PDO and Prepared Statements to protect against SQL injection. This example acquires user input from $_GET[''] Super Global Variables, switch to $_POST[''] if that works better in your situation.
<?php

header('Content-Type:text/html; charset=UTF-8');

require_once 'HTMLPurifier.standalone.php';

$servername = "localhost";

$username = "user5";

$password = "USER5password";

$dbname = "contacts";

$firstname = $_GET['firstname'] ?? 'first';

$lastname = $_GET['lastname'] ?? 'last';

$email = $_GET['email'] ?? 'email';

$purifier = new HTMLPurifier();

$firstname = $purifier->purify($firstname);

$lastname = $purifier->purify($lastname);

$email = $purifier->purify($email);

try {

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$sql = "INSERT INTO guests (firstname, lastname, email)

VALUES ('$firstname','$lastname','$email')";

$conn->exec($sql);

echo "New record created successfully";

} catch(PDOException $e) {

echo $sql . "
" . $e->getMessage();

}

$conn = null;

?>