Bookstack Autosave

For those of you who have implemented Bookstack Add On without https, and are using solutions like Cloudflare Tunnel or a Web Proxy to provide HTTPS encrypted access, you are likely to experience issues with autosaving documents while you edit.
I solved this by adding an additional environment variable:

- name: APP_URL
  value: https://domain.tld  (replace domain.tld with your own)