add fallback feature

rasa/config.yml

@@ -36,7 +36,7 @@ pipeline:
     epochs: 100
     constrain_similarities: true
   - name: FallbackClassifier
-    threshold: 0.3
+    threshold: 0.7
     ambiguity_threshold: 0.1
 
 # Configuration for Rasa Core.

rasa/data/rules/rules_basics.yml

 version: "3.1"
 
 rules:
+- rule: ask the user to rephrase whenever they send a message with low NLU confidence
+  steps:
+  - intent: nlu_fallback
+  - action: utter_could_not_understand
+
 - rule: respond to a thankful user
   steps:
   - intent: thank_you

rasa/domain.yml

@@ -65,6 +65,13 @@ actions:
   - action_future_iss_location
 
 responses:
+  utter_could_not_understand:
+  - text: "I'm sorry, I didn't quite understand that. Could you rephrase?"
+
+  #######################################################
+  #######################################################
+  #######################################################
+
   utter_your_welcome:
   - text: "You're welcome! I am always happy to assist you."
   - text: "Of course! If you have any other question or request feel free to ask them!"