Podcast Chapters

Is it possible to add chapter marks with Mp3tag? I saw there was some podcast support but i couldn't find out how to add chapter marks or what the input format should be. In Auphonic you can add chapter in a couple of ways. Adding in their UI like this https://auphonic.com/media/blog/cm_auphonic.jpg or import with a file formatted the way you get labels exported from Audacity or the way mp4chaps is formatted. If there is support for this what format should i use?

I tried to reverse engineer by adding a file to Mp3tag that had chapter marks and see if the input fields showed up but they didn't.

No.