if not sure, look in your manual to check/read gearbox oil. if don't have, maybe manual se do not have dip stick (which is unlikely but i could be wrong). then go to the shop/mechanic and ask them to top up for you.
if you don't want to change/top up is ok, tell them you plan to change the gearbox oil (bluff to them) and ask them to check if it is still ok to drive or not...
ask them to check in front of you and if they give you funny ideas (like ohh....cannot drive anymore, have to change.....if drive couple of days, then gearbox will spoilt or some stupid story), tell them it's ok. i am a bit hurry for time, i will let you know when to come next/or tell them a story. then, being careful, go to another shop/few shop and ask them the same. if they tell you same story, then better check it out.
if your car is still under waranttee, go back to eon to check out for you. some people will ask you better not but i used to send my car to eon for certain repairs (major/unique repairs which require eon expertise).
once the mechanic show you how to check, then go back and do this check regularly. happy DIY