Debug TiDB Cloud Documentation: Connect to TiDB Serverless via Public Endpoint

This issue is a sub-issue of Debug TiDB Cloud Documentation: Summary Issue · Issue #15480 · pingcap/docs. The purpose of this sub-issue is to verify and debug the Connect to TiDB Serverless via Public Endpoint document.

You can follow the instructions provided in #15480 to verify and debug the instructions in this document.

1. After finishing your verification, please add your verification result to this sub-issue as a comment. The result can be the issues you encounter, the mistakes you find, or any other findings. If everything looks fine, you can also add it as a comment.
2. For any issues you found during the verification, welcome to create a pull request (PR) to fix them directly. In the pull request, please indicate which issue this PR resolves in the PR description (for example, fix #15741). To learn how to create a pull request, see TiDB Documentation Contributing Guide.

Note: Currently, the TiDB Cloud documentation is in English only and it is stored in the release-7.5 branch of pingcap/docs for reusing the SQL documentation of TiDB. Hence, to create a pull request for TiDB Cloud documentation, make sure that your PR is based on the release-7.5 branch.

Your contribution to testing and verifying the documentation is highly appreciated!