peng cui Thanks for posting your question in Microsoft Q&A. You can debug Azure Functions in VS code to get PlayFab Title. Here is the doc: Calling your function using HTTP requests from Visual Studio Code which uses REST Client extension and also has sample code snippet to get the title.
Based on the exception, it looks like API endpoint was incorrect and suggest you validate and follow the steps in the doc. Currently, Azure PlayFab is not supported in Q&A forums. Please ask the experts in the dedicated forum https://community.playfab.com/index.html and the community experts can assist you with your questions. Supported products of Q&A forums are listed in https://docs.microsoft.com/en-us/answers/products/ (more to be added later). I hope this helps.