countryCode property
Optional - If omitted and the template has any conditions that depend on country_code, they will be evaluated as false.
Should be 2 lower-case letters, e.g. "us", "tr", or "gb", as defined in ISO 3166-1 alpha-2. This is case-insensitive. See https://www.iso.org/obp/ui/#search .
Implementation
core.String? countryCode;