Hi, is there a credit card we can use to pay home mortgages to earn points?

For mortgages I am not entirely sure...

But I know for rental or tax that is paid monthly, you can use services like CardUP and IPayMy.
These services will charge a fee on top of the amount you pay thus you are actually buying miles or points using those $$$ that you pay.

Hi, you could theoretically get points for paying your home mortgage by using third party payment apps like plastiq. Where you would pay plastiq using your credit card and they would pay your recipient afterwards via wire or bank transfer. Take note that they charge a flat transaction fee of 2.5% so if your credit card rewards and cashback is higher than 2.5% I would recommend you take a look at plastiq.