This seems to be all the information they give so I would submit a PDF. This does ask for extras along with the episodes. Make sure you're following that and following the 'episode' requirement. So have it set up for scrolling and not page by page. If you've already got it set up for tapas or webtoon file size just submit that. Compression is what it is, I wouldn't submit high-res art into the void for another company to access anyway. Just make sure it's not CRT TV levels of blurry.
