The different Italian resources are :

The parish registers.

The Council of Trent 1545-1563) nineteenth ecumenical council recognised by the Catholic Church (was a meeting of Catholic clergy convened by Pope Paul III (acting 1534-1549) in response to the Protestant Reformation . In three separate sessions, the Council reaffirmed the authority of the Catholic Church, codified the Scriptures, reformed abuses and condemned Protestant theology, setting out the vision and aims of the Counter-Reformation Catholic.
The Council imposed on the parish priest the responsibility for the religious services of a place of worship or a community. The keeping of parish registers, which include registers of baptisms (births), marriages, and deaths, will only appear later. They are kept in the parish of origin. There are also registers of the state of souls (Stato delle anime) which is the recent parish by parish record. This document includes the names of the persons, the dates and places of baptism, communion, confirmation, marriage, burial plus various additional information (such as military immigration).

Other information :

A duplicate was created to 1820 They are kept in the bishop's office.
In order to consult them, permission must be sought from the director of the diocesan archives.
Two copies are kept: in the town hall and at the court registry.
The religious archives, which record baptisms and marriages, are still used as a civil registry.

Search for contact details of dioceses and parishes:

List of dioceses and archdioceses in Italy - Wikipedia
Chiesa Cattolica (Catholic Church) - Official website of the Catholic Church in Italy - Offers information on all dioceses in Italy.
Chiesa Cattolica - Find parish addresses. To find the postal or e-mail address of the dioceses in Italy.
SittiCattolici (Catholic websites) - The Italian portal contains a list of links to sites related to Catholicism and each link is described in detail. The list includes links to the pages of parishes and dioceses.
ParrocchieWeb (Web parishes) - Another Italian portal offers a map of parishes with records of parishes have a website organised by region. In the left menu, select the region of interest in the Mappa Parrocchie.
Parrocchie.it - Database of parishes in Italy, information on more than 25.000 parishes in Italy.
Parrocchie Map - Other database.
https://genealogieitalienne.com/registres-paroissiaux-en-italie/

Civil status

Civil status registers (registri dello stato civile) include names, dates and places of births, marriages and deaths. They may contain documents necessary for the marriage, such as miscellaneous notes (stillbirths), death certificates from another city or country, and acknowledgements of paternity.

The Napoleonic period marks the beginning of civil status in Italy from 1805 to 1815. The registers of the Napoleonic Civil Registry" (stato civile napoleonico) are equivalent to the Belgian State Archives. In the North of the country it usually starts in 1860, in Piedmont in 1866, in Veneto 1870. They are called (stato civile italiano). In the South (ex-kingdom of Naples and the two Sicilies), it starts in 1820 and is called the "restoration" civil status (stao civile della restaurazine).

Registration of births, marriages and deaths began in many regions in 1809 (1820 in Sicily). In 1866 the registration of acts became compulsory by law. From this date onwards all individuals were registered. For research before 1809 or 1820 see the parish registers
To obtain a copy of an act, you can write to the town hall. The delays are very long. Sometimes you will only receive a certificate and not a complete copy of the act, in case of homonymy errors may be provided.
a copy in conformity with the Vienna Convention of 08/09/1976, approved by Italy on 21/12/1978 (law no. 870) can be requested.
Finally, you should know that the originals are held by the town halls, and a duplicate is kept at the court. Only registers older than 70 years are accessible.

Sources :
https://genealogieitalienne.com/registres-paroissiaux-en-italie/
https://genealogieitalienne.com/letat-civil-en-italie/