How to add additional fields to check out like total points earned on this purchase, add voucher etc

[paulson1]

Hi,

I am looking to add a few additional fields to the Checkout Page.

-Points Earned on this purchase, 

-Use Points (I am thinking of using smile.io and if the points are above 500 then it should allow customers to use points)

-Add Voucher (if the customer has any voucher code)

Could you please let us know what is the best way to do it?

Thanks