Serial Debug for Arduino UNO connected on USB

I understand from the instructions below that you can enable debugging - will this also work for a serial connected Arduino UNO? where can I find/follow that log?

Thx, Gernot

To enable debug prints on the default Serial, add on the top of your sketch (should be the first line ):

#define BLYNK_DEBUG // Optional, this enables lots of prints
#define BLYNK_PRINT Serial

And enable serial in setup():

Serial.begin(9600);

Yes, you’ll see all the incoming data from the app in the Serial Monitor

Sure, but keep in mind that UNO has 1 hardware serial.
It you connect blynk via USB, this serial is busy.
You can use SoftwareSerial to debug. Actually the Serial_USB example has everything in it.