Can existing Upstox customers open a 3-in-1 account?

Existing Upstox customers need to visit https://upstox.com/3-in-1account/IndusStox/transfer and follow these steps:
Sign in with an email address or mobile number and request for an OTP
Agree to the Terms & Condition of Upstox
Select the IndusInd Bank account which you want to link to your Upstox trading account
Agree to the Terms and Condition of Induslnd Bank
Your application will be sent to create your Induslnd Saving Account as a Primary Bank account with Upstox