Form is not submitting via Firefox - html

Question

I've a form that works perfectly fine on Chrome, Safari, but not Firefox.
Try#1
<form id="subscribe-form" class="footer-sign-up" action="/subscribe" method="POST">
<input type="text" placeholder="First Name" name="first_name" id="fname" required>
<input type="text" placeholder="Last Name" name="last_name" id="lname" required>
<input id="footer-email" type="text" placeholder="Your Email Address" name="email" required>
<input type="submit" id="subscribe" class="signupbtn" value="sign up">
</form>
Try#2
<form id="subscribe-form" class="footer-sign-up" action="/subscribe" method="POST">
<input type="text" placeholder="First Name" name="first_name" id="fname" required>
<input type="text" placeholder="Last Name" name="last_name" id="lname" required>
<input id="footer-email" type="text" placeholder="Your Email Address" name="email" required>
<button type="submit" id="subscribe" class="signupbtn">sign up</button>
</form>
result
Network Tab
Header
Params
How would one go about debugging this further?

Answer 1

I think I may have found something; if you're submitting via AJAX, but not preventing the page submit, you'll have an issue.
Change part of your code to:
$('#subscribe').click(function(e){
e.preventDefault();
...
This should only do the AJAX submit, and not refresh the page.
I was also able to submit via FireFox by changing button type="submit" to button type="button", so that it won't natively submit the page on press.

Answer 2

You need to add a CSRF token to your form. Assuming this is a blade file:
<form id="subscribe-form" class="footer-sign-up" action="/subscribe" method="POST">
{{ csrf_field() }}
<input type="text" placeholder="First Name" name="first_name" id="fname" required>
<input type="text" placeholder="Last Name" name="last_name" id="lname" required>
<input id="footer-email" type="text" placeholder="Your Email Address" name="email" required>
<input type="submit" id="subscribe" class="signupbtn" value="sign up">
When a page in Laravel loads, you can print a CSRF or Cross Site Request Forgery token which is good for a certain amount of time. Any POST request needs to have a current one of these, otherwise Laravel will give you a page expired error.