   {
     if ( htmlUnmodified( request, date ) ) return request->send(304);
     AsyncWebServerResponse *response = request->beginResponse_P( 200, HEADER_HTML, index_htm, index_htm_len );
-    response->addHeader( "Last-Modified", date );
+    response->addHeader( HEADER_LASTMODIFIED, date );
     request->send( response );
   });
 

  {
    if ( htmlUnmodified( request, date ) ) return request->send(304);
    AsyncWebServerResponse *response = request->beginResponse_P( 200, HEADER_HTML, logs_htm, logs_htm_len );
    response->addHeader( "Last-Modified", date );
    request->send( response );
  });


  {
    if ( htmlUnmodified( request, date ) ) return request->send(304);
    AsyncWebServerResponse *response = request->beginResponse_P( 200, HEADER_HTML, fileman_htm, fileman_htm_len );
    response->addHeader( HEADER_LASTMODIFIED, date );
    request->send( response );
  });

