Hi Abrar,
please check out the documentation on how to Build a Chatbot from Scratch Using the Blank GenAI App which is also useful for existing apps.
Furthermore, you can review the GenAI Showcase App or AI Bot Starter App for examples for chatbot integration (with knowledge bases or in-app data via function calling).
Specifically for agentic AI, you can also check out the Agent Builder Starter App which also contains a chat bot.
Best regards
Liam