How can PHP form submissions be handled without using JavaScript or the <input type="submit"> button?

When handling PHP form submissions without using JavaScript or the <input type="submit"> button, you can use a different type of form submission trigger such as a regular button with a name attribute and a form action that points to the PHP script handling the form submission. In the PHP script, you can check if the form has been submitted by checking if the button's name attribute is set in the $_POST superglobal.

&lt;form method=&quot;post&quot; action=&quot;submit.php&quot;&gt;
    &lt;input type=&quot;text&quot; name=&quot;username&quot;&gt;
    &lt;button type=&quot;submit&quot; name=&quot;submit&quot;&gt;Submit&lt;/button&gt;
&lt;/form&gt;
```

```php
if(isset($_POST[&#039;submit&#039;])){
    $username = $_POST[&#039;username&#039;];
    // Process form data here
}