I know you can close issues by putting closes #1 or fixes #1 in the commit message. What is the best way to close multiple issues in the same commi
"Closing issues using keywords" is a document from GitHub that describes how to close issues, tags and how to close multiple issues.
To answer your questions the answer from GitHub is:
Closing multiple issues
To close multiple issues, preface each issue reference with one of the above keywords. You must use the keyword before each issue you reference for the keyword to work.
For example, This closes #34, closes #23, and closes example_user/example_repo#42 would close issues #34 and #23 in the same repository, and issue #42 in the "example_user/example_repo" repository.