Leonardo use avrdude compile error

Hi Everyone,

I tried use avrdude.exe compile Blink.ino.hex error as 1.jpg.

My leonardo use USB Interface, but i upload success on Arduino 1.8.12 as 2.jpg.

You need to reset the Leonardo, wait a couple seconds, then immediately run the avrdude command. The tricky thing is that the COM port number changes when you reset the Leonardo. I can see from the Arduino IDE output you shared that the normal port number of your Leonardo is COM15, but the port number while uploading is COM18. So make sure your avrdude command uses COM18, not COM15.

The Arduino IDE does all that automatically. They way it works is the Arduino IDE opens a serial connection to the Leonardo at 1200 baud. The firmware running on the Leonardo sees that as a special signal to reset the microcontroller and activate the bootloader. The Arduino IDE waits for a new COM port to appear, and assumes that is the port to use for the upload.