https://www.desidime.com/discussions/credit-card-payment-thru-paytm-merchant-qr?page=1#post_8664782
you have to activate the option in payment sources and charges section...
from there you have to activate from which sources you like to accept payment like.. upi, wallet, postpaid, DC, CC and net banking..
except wallet and upi all other options have charges from 1-3% ..
so not helpful in any way.. also charges vary for different accounts
