A quick snippet to alter the HTML output of the Gravity Forms submit button

Place the below into your functions.php. Where it says gform_submit_button_6 you will need to change the number 6 to the ID of the form you want to target.

If you are running a theme, make sure you are using a child theme so your changes aren’t overwritten on theme updates

add_filter( 'gform_submit_button_6', 'landing1_submit_button', 10, 2 );
function landing1_submit_button( $button, $form ) {
	return "<button class='btn btn-lg btn-danger btn-block nomargin' id='gform_submit_button_{$form['id']}'>SUBMIT</button>";