For drones without C-class rating, which can't even be gotten yet because of SNAFU with specifying certifying process, it's all according to weight and environment you're in.
As long as drone has camera you need to register as drone operator in one EASA country, but for sub 250 gram drones there's no need to do
A1/
A3 online test.
But 30 day time to pass the test is included in registration cost at least here in Finland.
(both registration and passed test valid for up to 5 years)
And with
A1/
A3 "license" you can fly up to 25kg drone in sparsely populated places/outside commercial, industrial and residential areas. (
A3 operating category)
A2 license would allow flying up to 2kg drones in densely populatated areas up to 31 Dec 2022.
After which date
A2 license is usefull only for (up to 4kg) C2 class drones, with all above 250 gram limit "legacy" drones belonging to
A3.
EASA | European Union Aviation Safety Agency: The European Union Authority for aviation safety
www.easa.europa.eu
The ‘open’ category is the main reference for the majority of leisure drone activities and low-risk commercial activities.
www.easa.europa.eu