Live Nifty50 Data to Sheets

I already retrieve the Nifty 50 option chain through the DhanHQ access-token flow, but the 25-hour token expiry forces daily resets. I now want the same feed driven by my permanent DhanHQ API key so the process runs hands-free and does not interfere with any other calls I make to the platform.

What the finished solution must do
• Authenticate with DhanHQ using my API key (or, if you can demonstrate a cleaner route, an equivalent key-based broker such as FYERS).
• Pull the full option chain in real time and place each contract on its own row inside Google Sheets, showing Strike Price, Open Interest, and Last Traded Price.
• Refresh automatically every minute during market hours without manual action.

You may script this in Google Apps Script, Python pushed to a Cloud Function, or any stack that keeps the sheet alive and editable. I just need to be able to paste my key, set the refresh interval if required, and watch the data flow. Clear inline comments and a short setup guide are expected so I can maintain or extend the script myself.

The job is done when the sheet holds a stable, minute-by-minute feed of Strike, OI, and LTP for all Nifty 50 contracts through two full trading sessions.