The code below is an example in how to add an admin page to your WordPress website – you can use the example below as starting point, minimal changes are required.
add_action('admin_menu', 'awesome_page_create');
function awesome_page_create() {
$page_title="My Awesome Admin Page";
$menu_title="Awesome Admin Page";
$capability = 'edit_posts';
$menu_slug = 'awesome_page';
$function = 'my_awesome_page_display';
$icon_url="";
$position = 24;
add_menu_page( $page_title, $menu_title, $capability, $menu_slug,
$function, $icon_url, $position );
}
You can find more information in how to add page admin on the links below.