For reference, here are the help articles on importing.
https://proconnect.intuit.com/support/en-us/help-article/import-export-data-files/importing-data-pro...
And as usual, a few are broken.
I think https://proconnect.intuit.com/support/en-us/help-article/import-export-data-files/prepare-export-cli... is the article you want.
