Publisher .pub files on a MacBook Pro

The free open source application called LibreOffice using LibreDraw can open and edit .pub files.

https://www.libreoffice.org

The current free LibreOffice Suite (e.g. 7.5.5) can open Microsoft Publisher documents but it is not an editor for them. It is my recommendation to only download LibreOffice from the Document Foundation site and not from the Mac App Store.

If you need the ability to open, edit, and save Microsoft Publisher documents, then it is likely you need access to Office 2021 Professional Plus for Windows to handle these documents in their native format. I don't see any tools to do this in the Mac App Store that have more than a single-star review, or actually are reported to do what they claim — at any price.

Have a look at LibreOffice for Mac and is available on the Apple Apps Store at a cost or get the Donation Version directly from the Developers

There are some reports is can Open the older PUB files but can not export them

I don't believe publisher plus is a Microsoft app. You might be better served by contacting Microsoft support to see what, if any, options you may have.