How come I am not able to convert the chapters?

Thank you for using our software. Do you want to split audible into chapter or convert audible with chapters withou splitting?
For splitting audible into chapters: please click on option button>>split by chapters>>ok. Go back to the main interface to click on "Convert to mp3/m4b". Once finished you'll get the audible books converted and splitted into chapters.

For converting audible without splitting into chapter but with chapter information preserved, please choose to 'convert to m4b".

For detailed guide, please read: https://www.epubor.com/easiest-way-to-preserve-chapters-while-converting-audible-audiobooks.html