Hi,Change Company Country:

Go to Settings -> Users & Companies -> Companies.

Select your company.

In the General Information tab, find the Country field.

Change the country to your desired country.

Save the changes.

Update Users’ Country:

Go to Settings -> Users & Companies -> Users.

Select each user and go to the Preferences tab.

Change the Country field if needed.

Save the changes.

Update Localization Settings:

Go to Settings -> General Settings.

Scroll down to the Localization section.

Update the Country field if it’s available.

Check Fiscal Position:

Go to Invoicing -> Configuration -> Fiscal Positions.

Ensure that the fiscal position aligns with the new country’s tax requirements.

Update Partner Records:

If necessary, update the country for key partner records (e.g., customers and suppliers).

Go to Contacts -> Customers or Suppliers and update the country field for each record.

Hope it helps

Hi,
If its a fresh db, you can change the country from the company master.

Update:

Step-by-Step Guide to Change the Database Country in Odoo 15

1. Change Company Country:
   • Go to Settings -> Users & Companies -> Companies.
   • Select your company.
   • In the General Information tab, find the Country field.
   • Change the country to your desired country.
   • Save the changes.
2. Update Users’ Country:
   • Go to Settings -> Users & Companies -> Users.
   • Select each user and go to the Preferences tab.
   • Change the Country field if needed.
   • Save the changes.
3. Update Localization Settings:
   • Go to Settings -> General Settings.
   • Scroll down to the Localization section.
   • Update the Country field if it’s available.
4. Check Fiscal Position:
   • Go to Invoicing -> Configuration -> Fiscal Positions.
   • Ensure that the fiscal position aligns with the new country’s tax requirements.
5. Update Partner Records:
   • If necessary, update the country for key partner records (e.g., customers and suppliers).
   • Go to Contacts -> Customers or Suppliers and update the country field for each record.

From: https://www.odoo.com/forum/help-1/how-to-change-the-database-country-in-odoo-15-253884

Thanks