How to include Api Subscription key of Custom Question Answer in Azure Bot Service Web App

Question

In Azure AI Bot Service, I have added Custom Question Answer Service Endpoint to the Bot Service Message Endpoint.
But I am unable to find where to add subscription key to the bot.

Also, Direct link to create a bot from Custom Question Answer deployment not working.
Any suggestions?

Answer 1

Hi Sonali Vaghela,

Welcome to Microsoft Q&A forum. Thanks for posting your query.

Since your bot is calling the Custom Question Answering (part of Azure AI Search & Language Services), it needs an API key for authentication. The API key should be added to the request headers. Follow these steps:

Option 1: Add Subscription Key in Bot Code (If You Have Code Access)

If you have access to your bot’s code (in a Bot Framework SDK or Web App Bot), include the API key in the HTTP request headers:

import requests
API_ENDPOINT = "https://<your-custom-question-answer-endpoint>/language/:query-knowledgebases"
SUBSCRIPTION_KEY = "your-subscription-key"
headers = {
    "Ocp-Apim-Subscription-Key": SUBSCRIPTION_KEY,
    "Content-Type": "application/json"
}
data = {
    "question": "your question",
    "top": 3
}
response = requests.post(API_ENDPOINT, headers=headers, json=data)
print(response.json())

Replace <your-custom-question-answer-endpoint> with your actual Azure Custom Question Answering endpoint.

Option 2: Add API Key in Azure Bot Configuration (If No Code Access):

If you are using Azure Bot Service without direct code access, follow these steps:

Go to Azure Bot Service:

Open Azure Portal → Navigate to Bot Services → Select your bot.

Set the API Key as an Application Setting:

Go to Configuration in your bot's App Service.

Under Application settings, click New application setting.

Add:

Name: QNA_SUBSCRIPTION_KEY

Value: your-subscription-key

Click Save.

Modify Bot Service Endpoint (if required):

Open Bot Service → Settings → Messaging Endpoint.

If using a proxy, ensure it forwards the Ocp-Apim-Subscription-Key header.

Direct Link to Create a Bot from Custom Question Answer Not Working:

If the direct link is not working, try the manual approach:

Step 1: Deploy a Custom Question Answering Service

• Go to Azure AI Services.
• Search for Language Services → Create a Custom Question Answering (CQA) resource.
• Note the endpoint URL and API key (found in Keys & Endpoint).

Step 2: Create a New Bot Manually

• In Azure Portal, go to Bot Services → Click Create.
• Choose Web App Bot or Bot Framework SDK.
• Under Cognitive Services, add the Custom Question Answering endpoint manually.

Final Checks:

Verify that the subscription key is valid from Azure Cognitive Services → Keys & Endpoints.

Use Postman to check if your API is responding correctly.

Check Bot Logs (Application Insights) for request failures.

Hope this helps. Do let us know if you any further queries.   

------------- 

If this answers your query, do click Accept Answer and Yes for was this answer helpful.

Thank you.

Answer 2

Hi @Prashanth Veeragoni

Thanks for your reply.
Currently I am not creating bot from code. I am using Azure AI Bot service.

In the creation, I have already entered the My Custom question answer message endpoint. But I am unable to find where to enter it's subscription key.

I have already tested the APIs of custom QnA in postman and it's working fine.

There is no application setting thing that you have suggested.

I have gone through below steps to create bot.

Go to Azure Bot -> Create New -> Type of App (Multi Tenant) -> Review & Create

After creating in the configuration section, I am writing message endpoint.
While clicking on "Test in Web Chat", it is throwing "Unauthorized" error.

Am I doing anything wrong in that?