trying this

Author: quinn-dougherty

Dockerfile.dash

@@ -10,8 +10,6 @@ RUN pip install -q -r requirements.txt
 
 COPY . .
 
-ARG PORT
-
 EXPOSE $PORT 
 
 CMD gunicorn src.dash_app:server --bind 0.0.0.0:$PORT

heroku.yml

@@ -1,5 +1,5 @@
 build:
   docker:
     web: Dockerfile.dash
-  config: 
-    PORT: ${PORT}
+    #  config: 
+    #    PORT: ${PORT}