Please try below steps to flash the firmware via computer:
It can be done with the camera turned off.
(Please try not to insert the sd card and the battery in the camera while reflashing.)
and “DirectUSB-126.96.36.199-Setup.exe” to your computer.
2. Hold the WiFi button and at the same time, connect it to computer via USB port. Then you will see two devices in device manager as showed below:
3. Open the attachment file download.zip and find FRM and click it and then set as we showed in below screenshot and click ISP. The flashing starts. A few minutes later, it will show ISP finished and flashing is done.