A simple Worker for converting SRT subtitles to WebVTT on the fly. Based on the built in converter from OPlayer.
https://<your-worker-url>.workers.dev/?url=<url-of-remote-srt>
https://srt-to-vtt.streamnorth.ca/?url=https://durian.blender.org/wp-content/content/subtitles/sintel_en.srt