Change language of Collabora online to Italian

Hi all

i have installed Collabora online on my Linux server (Ubuntu) manually, and I have linked it to Nextcloud without any problem.
I would like to use the menus in Collabora in Italian language
what should I do? if there is a step-by-step procure I would be very thankful.

i have noticed that if I have created a new document using a user with English language the menu remains in English,
while creating a new file using a user with Italian language the menu remains Italian.