function redirect_plain_cms_to_frontend() {
if ( isset( $_SERVER['HTTP_HOST'] ) && 
	$_SERVER['HTTP_HOST'] === 'cms.example.ee' || 'stage.cms.example.ee') {
	$request_uri = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '/';  
    if ( ( $request_uri === '/' || $request_uri === '/index.php' ) ) {  
       wp_redirect( 'https://example.ee', 301 );  
       exit();  
    }  
  }  
}  
add_action( 'template_redirect', 'redirect_plain_cms_to_frontend' );