Hi,
I bought an OpenEVSE in the US while I’m in France, I discovered that you have an EU software for three-phase and single-phase charging. I bought this USB key that allows OpenEVSE updates only I’m afraid of doing something wrong.
Can you tell me which version of software is used as well as the checks to be carried out before?
Since the OpenEVSE is unavailable it would be disturbing to break it 
if you have another tutorial than this one I would like it thank you https://openevse.dozuki.com/Guide/How+to+Load+OpenEVSE+Firmware+(WinAVR)/7
Thank you for your help
You can get the latest firmware from Release 8.2.0 · OpenEVSE/open_evse · GitHub
For 3 phase in the EU you probably want the emonevse_3ph.hex, for single pase use the openevse_eu.hex if you have a tethered cable else the emonevse.hex for a removable cable.
The guide you pointed to for flashing looks correct to me. It is a relatively safe process to flash the OpenEVSE, I have done it many time without issue, but there is a very small chance you could brick the EVSE.
Using USA firmware on an OpenEVSE in Europe is not a big problem. The only differences are default to Level 2 and set 32A max current. The three-phase version also calculates energy assuming current draw on 3x phases.
You can Level 2 and 32A via the interface, and you can fix the energy calculation in Emoncms by applying a 3x scaler input process. It’s not an issue if the max current is set at higher than 32A since 32A per phase is the max that all EVs in Europe will charge at, setting the pilot signal higher than this will have no effect.