Has anyone effected Duitnow QR payment using bank app linked to credit card account instead of the usual CASA method?

Say I only have a credit card with A Bank, and I use A Bank's app to scan the merchant's Duitnow QR to effect payment using the credit card as the (sole) source of funds.

I read HSBC and CIMB have these in their FAQs. But I tried scanning a merchant's Duitnow QR to pay but was told I didn't have the necessary account to pay using Duitnow QR function.

Oh.. means there IS this function. Merchants' option to opt-out.