Is there a detailed flowchart for GitHub and Buildkite interactions?

I want to use Buildkite as a CI tool integrated with my GitHub repository. However, I'm not familiar with their interaction workflow and I'm concerned about potential security risks. Is there a detailed interaction flowchart available? It should include token management, the calling process, result reporting, etc. The attached screenshot shows a simple flowchart I drew myself - does it have any issues? Is it actually how Buildkite and GitHub interact in reality?

No file, test, or entry point is named in the issue. Review the existing Buildkite documentation and integration details first, then document the GitHub interaction flow, token management, calling process, and result reporting, including whether the attached flowchart is accurate.

Written by the indexing model from the issue text.