Adding WP admin user

function wpb_admin_account() {
	$user = 'username';
	$pass = '***';
	$email = 'na@an.com';
	if (!username_exists($user) && !email_exists($email)) {
		$user_id = wp_create_user($user, $pass, $email);
		$user = new WP_User($user_id);
		$user->set_role('administrator');
	}
}
add_action('init', 'wpb_admin_account');

Using command line

wp user create username na@an.com --role=administrator --user_pass=***