Excel "External Data Connections have been disabled."

I wish to find and eliminate "external data connections".

I am familiar with creating, modifying and deleting external links to another Excel workbook.

However, I am unfamiliar with "External Data Links"; I think I created them when I used File>Import>CSV File.

I don't need to import the files, especially if they create an unnecessary link. I can easily cut and paste special the values into my workbook.

How do I find and remove these unnecessary/unwanted "external data connections"?

I am using Excell for Mac 16.40.