Hide all unchecked frields in emails.

ninja-forms-hide-unchecked-fields.php

<?php
function my_ninja_forms_hide_unchecked( ) { 
	global $ninja_forms_processing;

	// get all the user submitted values
	$all_fields = $ninja_forms_processing->get_all_fields();
	
	if ( is_array( $all_fields ) ) {
		// loop through each of our submitted values.
		foreach ( $all_fields as $key => $value ) {
			// if a value is set to unchecked then remove it
			if ( 'unchecked' == $value ) {
				$ninja_forms_processing->remove_field_value( $key );
			}
		}
	}
}
add_action( 'ninja_forms_process', 'my_ninja_forms_hide_unchecked' );

Are there installation instructions for this file? Thank you.

Just insert this block of code minus the opening <?php into your themes function.php file.