There are two ways to select a country for your session.
User Dashboard V2
1.) Navigate to Services Residential Premium page https://app.geonode.com/services/residential-premium
2) Under Proxy Configuration, you will see a Country Targeting option
3) Select Country and Port
4) Press add
Via The API
To set a specific country for your session you need to add the parameter country-xx to the username.
Define the county by using two character ISO standards for country codes. A full list of country codes can be found here https://en.wikipedia.org/wiki/List_of_ISO_3166_country_codes
Example: When defining United States as country-us
Replace "username" with your username.
curl -x rotating-residential.geonode.com:10000 -U username-country-us http://example.com