What's the actual procedure to update firmware

Could someone please tell me what is the correct current procedure to update the RAK811 Breackout board firmware?

at+version
OK V3.0.0.13.H.T3

at+get_config=device:status
OK Board Core:RAK811
MCU:STM32L151CB_A
LoRa chip:SX1276

I have tried both procedures without success:
RAK DUFT 1.4 and SMT32CubeProgrammer

Resolved!
Something was wrong when I initially tried to configure the module in boot mode.
The initial step should be to load the .hex file using STM32CubeProgrammer.
Now my module has the latest firmware version. I understand that the DFU tool 1.4 can be used from now on?

If the firmware version you have now is V3.0.0.14 and up, you can now use DFU tool 1.4 for future upgrades.

That’s rigth, I have now V3.0.0.14 firmware. Thank you!