def default_source(self) -> RepositoryConfig:
        """Get the default source from the pypi setting"""
        config = RepositoryConfig(
            config_prefix="pypi",
            name="pypi",
            url=self.config["pypi.url"],
            verify_ssl=self.config["pypi.verify_ssl"],
            username=self.config.get("pypi.username"),
            password=self.config.get("pypi.password"),
            ca_certs=self.config.get("pypi.ca_certs"),
            client_cert=self.config.get("pypi.client_cert"),
            client_key=self.config.get("pypi.client_key"),
        )
        return config
Get the default source from the pypi setting
src/pdm/project/core.py