Fetch prefect host and test

lolafect/lolaconfig.py

@@ -155,6 +155,17 @@ class LolaConfig:
             "port": self.ENV_DATA["datadw_port"],
         }
 
+    @_needs_env_data
+    def fetch_prefect_host(self, s3_reader=None) -> None:
+        """
+        Read the env file from S3 and store the prefect_host.
+
+        :param s3_reader: a client to fetch files from S3.
+        :return: None
+        """
+
+        self.PREFECT_HOST = self.ENV_DATA["prefect_host"]
+
     def fetch_env_data(self, s3_reader=None) -> None:
         """
         Read the env file from S3 with the default or a passed s3_reader and