Hello,
How we can sell holding stocks using API as it requires OTP.
We recommend activating the DDPI to eliminate the need for the CDSL OTP verification process when selling holdings. For detailed instructions, please visit the following link: How do I activate DDPI (POA) on Upstox? - Upstox Help Center
Until you enable DDPI, you will have to perform the authorization process on https://pro.upstox.com before you want to sell.