Perhaps from Froggit. Download the latest software and then see if it will update firmware. There may not be one available. I'm just saying that it is a good thing to check.
Ah, I forget that there was a version before the SE version.
In that case install WeeWX and select station_type = FineOffsetUSB
That means I can use the Fineoffset driver instead of the old wh23xx driver which is not compatible with weewx4.x?