Connecting LED ceiling lamp - several cables hanging from the ceiling

Lol, this is the classic drama with electrical topics again. Electricity is just as potentially deadly as a knife, a brick, or a shoelace. It depends on the application. You have 3 cables. One of them is the live wire. You can easily find it with a voltage tester, better known as a liar pen. It should be the black conductor. The other two cables are neutral and probably earth. Is an RCD installed in the distribution board? If yes, you will quickly notice what earth is if you connect it instead of the neutral and turn on the lamp. Then the RCD trips. If you don't have an RCD, it doesn't matter whether you connect neutral or earth. Does the lamp even have a replaceable bulb? As far as I can tell, no. Are any metal parts accessible from the outside? I guess for you brown is neutral and grey is earth. Someone once fiddled the green cable on to mark that. If it is red and not brown, might be right, then it is the other way around.

Always hire a professional for electrical and water work!!!

... when you have no clue yourself. ;)

... if you have no idea yourself. ;)

I recently did something myself. But the cable was already there, I replaced it. Otherwise no desire for intensive.

Then please also have the printer and IT in general installed at home by a professional.

Printers and IT in general are SELV, there is no danger to life and limb.