In iMazing 1.3, we slightly changed how archiving backups works:
Import iMazing File Load from Archive has become Import iMazing File and behaves slightly differently: the .imazing backup file will be decompressed in the default backup location, and remain there until deleted manually. The .imazing file isn’t affected.
Export as iMazing File Export to Archive has become Export as iMazing File.
It behaves exactly as before: a .imazing file ( essentially a zip of your backup ) will be generated at the chosen location.