Hi,

The PostgreSQL details can be specified in the Odoo configuration file. The IP address of the Postgres server can be found in the db_host field, along with the database port, user name, and password.
For more reference you can refer to this: https://www.cybrosys.com/odoo/odoo-books/odoo-15-development/ch2/
https://www.odoo.com/it_IT/forum/assistenza-1/how-to-connect-odoo-with-postgresql-146966

Hope it helps

Hi Elisabetta ,

To connect Odoo with PostgreSQL, you need to find odoo.conf file and configure Odoo's settings to point to your existing PostgreSQL installation. 

pg_path = path_to_PostgreSQL_bin ; eg: C:\Program Files\PostgreSQL\10\bin

db_host = localhost ; PostgreSQL server address (usually localhost if it's on the same machine)

db_port = 5432  ; PostgreSQL server port (default is 5432)

db_user = your_username  ; PostgreSQL database username

db_password = your_password  ; PostgreSQL database password

Hope it helps,
Kiran K