Unable to add UPI as an option for collecting payments

Hello.
We recently started our e-commerce journey with Shopify, in India. We have two questions related to payments and billing.
Firstly, while adding payment options (our payment gateway is through a third-party vendor) only card payment options are reflected. Other options of UPI, Bank Transfers, etc. are not being shown. Although our payment gateway partner offers all options and have been functional, we are unable to use it on Shopify. Is there a way we can fix this?

Secondly, we want to change our billing source from the current UPI ID to another. We do see an option for changing it to card payments but not for changing it from one UPI account to another. How may we do so?

Thank you for your time.
Regards,
Team Encee.

Thank you for your clear instructions and quick assistance to this matter Shamad. We followed the steps mentioned by you and have both queries cleared now. Much appreciated.

Stay well,
Team Encee.