I use 6 years before Paytm marchent, using payment link.
By using Paytm business website you can sent payment Link with customized or non customised payment amount.
You just need to fill mobile and email paytm will sent payment Link that number. Then need to click the link and you can pay using paytm app with debit credit UPI prepaid and net banking also upto 2k without any changes. Now it's maybe charge 0.4 % . But now only showing invoice and the link also not working.