Wireless Shell Bootloader

One of my Wireless Shells seem to have lost its boot loader, using the Arduino IDE there seems to be no response when uploading a new firmware. Using the ESP-IDE I don’t seem to be able to be able to do an
esptool.py --chip esp32 -p COM5 erase_flash
There just seems to be no communications to the device.

What is the process for re-installing the bootloader and where can I find the original to bring it back to factory?