Website database issue... [PHP, MySQLi, HTML] - php

Question

So I am working on this under construction page for my own small business's website. I want to have an email field so that users write their email so that i can later tell them when the page is finished. But I am having trouble with the database. Apparently the connection is established but the data is not being written to the table in the DB. This is my php code, it is embedded on the top of my index.html:
<?php require 'connections/connections.php'; ?>
<?php
if(isset($_POST['submit'])) {
$Fname = $_POST['first_name'];
$Lname = $_POST['last_name'];
$Email = $_POST['email'];
$sql = $con->query("INSER INTO subscriptions (Fname, Lname, Email)Values('{$Fname}', '{$Lname}', '{$Email}')");
header ('Location: confirm.html');
}
?>
This is my connections.php file, required by the above code:
<?php
$con = mysqli_connect("localhost", "webmaster_velez", "Cristianpromw3", "nexus_subscriptions");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>
This is the HTML that the user interacts with to send their email address:
<div id="subscribe">
<form id="SubscriptionForm" name="RegisterForm" method="post">
<div class="FormElement">
<input name="first_name" type="text" required="required" class="TField" id="first_name" form="SubscriptionForm" placeholder="First Name">
</div>
<div class="FormElement">
<input name="last_name" type="text" required="required" class="TField" id="last_name" form="SubscriptionForm" placeholder="Last Name">
</div>
<div class="FormElement">
<input name="email" type="email" required="required" class="TField" id="email" form="SubscriptionForm" placeholder="Email">
</div>
<div class="FormElement">
<input name="submit" type="submit" class="button" id="submit" form="SubscriptionForm" value="Submit">
</div>
</form>
</div>
Any help, corrections, and/or advice on this would be much appreciated and accepted. Thanks in advance.
PS. I am new to PHP and database/server dynamics.

Answer 1

From reading the code you've written, I would assume that the main problem you are facing is this typo - "INSER INTO" should be "INSERT INTO".
You'll also need to implement some try error blocks to catch if any errors are happening and protect yourself from SQL vulnerabilities/injections.