I stand corrected you will need a temporary permit to fly a 600kg.ULM in France along with the licence that goes with it.
The rules are here.
Microlight2019_pdf
I don’t have an answer but a rant :P I faced the same problem after moving from Dubai to Berlin. My LSA license wasn’t valid anymore and German ultraright regulations require you to write the exam in German. Since I didn’t have a choice I decided to get my PPL from Hungary as I was working remotely. It would be great if authorities start supporting English for ultralights too. Even though I have PPL I would like to rent Ultralights due to their cheaper rental price and some experimental ultralight aircraft have better avionics than 50-year-old Cessnas.
As I posted in France you don’t need to take a theory test to get a ULM licence if you already have a PPL.
This ultrlight school is likely to know what you need. AFAIK they are also importers.
BR
Luis