You have about 1 to 2 seconds for this during which the bootloader is active.
If that doesn't help, use an ICSP programmer, connect it to the ICSP header and choose "Upload bootloader".
You have about 1 to 2 seconds for this during which the bootloader is active.
If that doesn't help, use an ICSP programmer, connect it to the ICSP header and choose "Upload bootloader".