I have upload a video demo in YouTube ,follow me.

https://youtu.be/4sA4mPmDFzs?si=0njlEI5IADUwLXOr

1,  Enter flash mode

sudo curl   https://www.bi7jta.org/files/MMDVM_Firmware/repeater_HAT/reboot_flash/1.enable_flash_mode.sh | sudo sh

If your NextionDriver service running , stop and disable it
sudo systemctl stop nextiondriver.service;
sudo systemctl disable nextiondriver.service;

2, Manual operation

Disconnect Power supply, ---->> PowerOff ---->> Short BOOTO on the board  ---->> Power ON​​

Once enter Flash Mode, you can take off the BOOT Jumper

3, Run flash script

sudo curl  https://www.bi7jta.org/files/MMDVM_Firmware/repeater_HAT/reboot_flash/2.booto_flash_cumbriacq.com_FM-Network.sh | sudo sh

4, Exit flash mode

sudo curl  https://www.bi7jta.org/files/MMDVM_Firmware/repeater_HAT/reboot_flash/3.exit_flash_mode.sh | sudo sh

If your NextionDriver service running , enable it
sudo systemctl enable nextiondriver.service;

5, Manual operation

Disconnect Power supply,  Disconnect Booto Jumper ---->> PowerOff ---->> Power ON​​

Tools:  WebSSH, Windows PowerShell, WinSCP,