Just in case you or another reader doens't know (you probably do), it is very easy to configure MacOS to by default open .txt or .json (or whatever) files in the app of your choice, such as ST. I have ST opening .txt and .json, yeah.
https://support.apple.com/guide/mac-help/choose-an-app-to-op...
(There's also prob some way to do it from terminal, but I do it the above way)