gramjs-session-file
Convert telethon .session file to StringSession for gram.js
Installation and use
npx gramjs-session-file
Or you can also install using npm:
npm i -g gramjs-session-file
Then run gramjs-session-file
in your terminal, specify the path to the .session file (you can also specify a whole directory with .session files for bulk converting) and after that specify where the sessions.json file with your StringSessions will be saved