Convert EPUB3 into another format

Hi all,

I hope you are well.

I have a Sony PRS-T2, and I would like to download a book from Kobo. It says, 'Download options: EPUB 3 (Adobe DRM).' However, I am aware that the Sony PRS-T2 doesn’t support this format. I also understand that software like Calibre can convert the format. What format should I convert it to? Should it be EPUB1, EPUB2, PDF? Would it work?

Thanks