I'm getting this error on Arduino(1.8.9).
usage: esptool write_flash [-h] [--erase-all]
                       [--flash_freq {keep,40m,26m,20m,80m}]
                       [--flash_mode {keep,qio,qout,dio,dout}]
                       [--flash_size FLASH_SIZE]
                       [--spi-connection SPI_CONNECTION] [--no-progress]
                       [--verify] [--compress | --no-compress]
                       <address> <filename> [<address> <filename> ...]
esptool write_flash: error: argument <address> 
<filename>: [Errno 2] No such file or directory:'/home/USER/.arduino15/packages/esp32/hardware/esp32/1.0.2/tools/partitions/boot_app0.bin'
esptool write_flash: error: argument <address> <filename>: [Errno 2] No such file or directory: '/home/USER/.arduino15/packages/esp32/hardware/esp32/1.0.2/tools/partitions/boot_app0.bin'
Although boot_app0.bin file is present: image link
 
                        
if you are using esptool. Make sure you actually download the files from github using the download button instead of using the save as option when u right click on the file name.