Mi hanno regalato questa plafoniera ma non so come montarla sul soffitto. Potete aiutarmi?

Add valaisinpistotulppa to the lamp and attach that to ceiling. Plug costs around 3-5€ depending where you get it.

https://preview.redd.it/ikv678iunvfd1.jpeg?width=739&format=pjpg&auto=webp&s=2a0f3c254bb16268cb59edd90238a4a5303e8aa3

Also there seems to be hanging holes inside the lamp. Put one of them to hook on the ceiling.