add a note to tell user about env vars

README.md

@@ -22,6 +22,9 @@ version = "0.0.1-SNAPSHOT"
 
 3. In your springboot project, add `application-local.yml` in `build/resources`
 
+**NOTE: Ensure there is no FIRETAIL_URL and FIRETAIL_API_KEY variable in your environment,**
+        **else this will override your yaml file configuration**
+
 ```yaml
 firetail:
   apikey: "PS-02....441b09761c3"