1. method 1

https://dialedin.com.au/blog/sonoff-zbdongle-e-rcp-firmware

Zigbee (EZSP) 6.10.3.0 build 297 -> 7.3.1.0 build 176
Sonoff ZBDongle-E

2. method 2

https://dongle.sonoff.tech/sonoff-dongle-flasher/

Current Device: ZBDongle-E
Current FW: Zigbee 8.0.2

3. reference

https://www.zigbee2mqtt.io/guide/adapters/emberznet.html