The default format on iTunes is AAC, and Jooki2 supports MP3 files.
Assuming the files you want to transfer are DRM-free, you can convert your files to MP3 with iTunes.
1. Select the songs you want to convert to MP3. To select multiple files, press Ctrl on Windows or Command on Mac and click each file.
2. Go to the File menu.
3. Select Convert.
4. Select Create MP3 Version.
5. Wait while the files are converted.
6. When the conversion from AAC to MP3 is complete, the iTunes Library contains a copy of the song in each format.
7. Open the Jooki desktop app you can download by visiting http://my.jooki.rocks from your laptop.
8. Select the .mp3 files and drag-drop the files into your playlist.