It can work on local or Heroku, but in order to give proper advise I needed to know which one you were having problems with. If you want to try and setup your own local server I have a guide for that: [GUIDE] Echo Speaks Server on Docker (or without) Some prior knowledge is assumed, it is not fully comprehensive.
For Heroku I have a solution for the 404 errors posted up above: [RELEASE] Echo Speaks V4 - #1717 by jtp10181
Funny thing is that I barley even use this app. I have a few TTS alerts setup and that's about it. But it is fun to tinker with and figure out, to help everyone else. I learned a lot of about Docker in an effort to figure it out for the community.
