Uses the built-in In-System Programming (ISP) bootloader via a standard serial (COM/UART) port.

: Supports loading and programming of Intel HEX and binary images. Advanced Buffer Operations

Click "Read Device ID" to confirm connection, then browse for your .hex file.

Always scan downloaded files with an antivirus tool. The official utility is a simple standalone executable or installer and should not require a "download manager" or browser extension to run.