You can calculate your marks by saving a copy of your responses as an html file, and uploading the file in the calculator
The answerkeys.js file contains answer keys as js objects
To generate new answerkeys, use the parseAnswerKey function present in main.js. Run it when on the answer key page provided by NTA. It will provide you with a js object representing the answerkey. Place this object in answerkeys.js and update the getAnsKey function in main.js
proxies.js contains a proxy variable, you can change it however you will also need to modify fetchResponseSheet in main.js accordingly
The default proxies are https://github.com/timepassuser/corsproxy, currently hosted on vercel and https://github.com/timepassuser/corsproxy-worker, a cloudflare worker.