I've converted a few fan fictions into audiobooks using edge-tts (https://github.com/rany2/edge-tts https://github.com/rany2/edge-tts). It uses a reverse engin

I've converted a few fan fictions into audiobooks using edge-tts (https://github.com/rany2/edge-tts https://github.com/rany2/edge-tts). It uses a reverse engineered API from MS Edge to use the more premium MS voices for free. A bit of a grey area, but it works remarkably well.