If you are facing issues with the UPI app, Try deleting the IPO order placed and apply using a different UPI ID linked with other UPI applications.
Alternatively, You can apply for an IPO through netbanking ASBA service provided by your bank if you don’t use UPI.
You need to fill in your Demat ID, Depository- CDSL, DP Name- Zerodha.
Check this post for a detailed explanation.