@Wesley Shen​ What is you error? We cannot help you with out any error messages.

It can come from a typo in your settings, a expired token, your firewall not giving you access to your cluster. There are a lot of issues possible.

You can also try to use the Spark SQL Agent (recently added in langchain), directly inside a databricks notebook.

https://python.langchain.com/en/latest/modules/agents/toolkits/examples/spark_sql.html