If you are living in Italy prior to 1st of January 2021, then your rights are different to those of new residents coming from the UK.
The Italian Government have created a Vademecum with details of your rights, and the card you can apply for that shows your rights are protected.
English Version of the Vademecum is here
Italian Version of the Vademecum is here this is extremely useful if you have to show someone that your rights are protected like your comune etc
The UK Government has a page that explains your rights in English clearly https://www.gov.uk/guidance/living-in-europe
The EU have a page that explains your rights under the Withdrawal Agreement
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