The only information sent from user's computer to https://api.github.com/gists is the information you pasted in the input box when you click the "Change Subtitle" button. The information transmitted to api.github.com will be used as a subtitle reference to be loaded when watching movies at https://123movieshub.to/. The servers behind api.github.com are owned by GitHub, Inc., and thus are unrelated to 123 Movies Hub Subtitle Changer.