Thank you for your help!
After I have connected the USB cable I press 3x the reset button on the MRK.
In the Device Manager >> I got a new port: COM3 - for the Arduino.
Then I checked the Port: COM in the IDE. It was now COM3.
And the Upload works well.
I use a Z370M-ITXac mainboard.
In the BIOS >> I select Legacy USB Support >> Legacy OS Support for USB 2.0 devices