fix

Author: v-thepet

articles/app-service/tutorial-ai-openai-chatbot-node.md

@@ -238,7 +238,7 @@ Yes, you can connect to Azure OpenAI using an API key instead of managed identit
 
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-### How does DefaultAzureCredential work?
+### How does the DefaultAzureCredential work?
 
 The `DefaultAzureCredential` simplifies authentication by automatically selecting the best available authentication method.