Last year IRS did not work in uploading an electronic 1099 file to the Internal Revenue Service's new IRIS system. I assume that it will for 2024. Can anyone provide a step-by-step guide on how to upload an IREFxxx.DAT file created in the Information Return System to the IRIS portal? Do you have to convert it to a CSV file?

This has been a very frustrating process to deal with. Any guidance and expertise is greatly appreciated. Thanks to one and all.