This video shows how to apply for an IPO with Zerodha using UPI. The procedure must be the same with any other non-banking Broker which uses UPI means for IPO.

Note that, funds for applying IPO will need to be with the bank account and funds in Zerodha cannot be used.

This is in a way is good, as the balance funds will be available in your bank account in around 10 days, once share allotment is done