Generate audio / TTS not working

Hello!
I wanted to try the “generate audio” function for an ebook that I uploaded.

the audio is stuck.
for example this is from the 1st chapter.
it says the whole audio is 25:03 but it only plays 0:44 and then it gets stuck.
same for the other chapters

Can you please send a lesson url to support(at)lingq.com? Thanks!