Uploading an Xcel Spreadsheet into a Particular Tag

I have watched the YouTube video regarding how to upload a CSV file.

I want to upload an Xcel Spreadsheet into my Contacts, but I want the names to go under the "Newsletter" tag for all the contacts in this file. How do I specifically upload this file so that the names in the spreadsheet are uploaded under my "Newsletter" tag?

Thank you. See screenshot.

After you click "Import Contacts" on the screen that you attached to this post - you will be asked for the Tag.