On September 7th 2020 the Government of Italy issued a new Decree (DPCM) that extends the previous rules till October 7th, 2020, The text of the Decree (in italian) can be found at this link: http://www.governo.it/it/articolo/proroga-delle-misure-di-contenimento-covid-19-il-dpcm-del-7-settembre-2020/15142
If you plan to return to Italy from abroad you will find useful information at the following link of the Ministry of Foreign Affairs and International Cooperation.
For a comprehensive snapshot of the various laws and regulations approved by the Italian Government please visit this link
Additional information in the form FAQ can be found at the following link.