How get the bot designed using Amazon Lex V2 to recognize Intents without sample utterances when its input contexts are active

To ensure that an intent without sample utterances gets triggered when all input contexts are active, you can use slot filling. When a user asks a question that triggers an intent with active input contexts but without sample utterances, the bot can prompt the user to provide more information through slot filling. The bot can ask questions to get more information and determine the appropriate response.

Here is an example:

Let's say you have an intent called "FindRestaurant" with active input contexts "City" and "Cuisine." The user asks, "What are some good restaurants in Boston?" The bot recognizes that the input contexts "City" and "Cuisine" are active and prompts the user to provide more information using slot filling. The bot can ask, "What type of cuisine are you interested in?" The user can respond with "Italian," and the bot can then provide a list of Italian restaurants in Boston.

Regarding your second question, there is no way to disable the fallback intent in Amazon Lex V2. The fallback intent is automatically triggered when the bot cannot match the user's input to any of the other intents. However, you can customize the fallback intent to provide a more meaningful response to the user.