WordPress plugins are great for adding additional features to a WordPress site. A good plugin really shines when it allows users to tailor the plugin based on their needs and requirements.
Once you’ve created a plugin menu link and settings page you need to add some a form that allows your user to save some values.
The code of your form is placed into the add_menu_page() function and passed as the function parameter.
add_menu_page( $page_title, $menu_title, $capability, $menu_slug, $function, $icon_url, $position );