What is the best way to organize a payment on the site?

Question

PHP

I actually organize the payment system on the site. using the interkassa as an example, I want to get some advice on how best to screw this whole thing up.
So the main point of the question is how best to organize accounts, that is, there is a payment form:

<form id="payment" name="payment" method="post" action="https://sci.interkassa.com/" enctype="utf-8">
                    	<input type="hidden" name="ik_pm_no" value="Номер счета" />
                    	<input type="hidden" name="ik_am" value="100.00" />
                    	<input type="hidden" name="ik_cur" value="USD" />
                    	<input type="hidden" name="ik_desc" value="Пополнение счета" />
                         ...

It requires you to enter "ik_pm_no" (Account number). Now the situation is when I do not want to strain the user to create an account, but for the user to enter the amount to replenish, replenish the account and only then write to the database that he replenished the account.
How do I deal with this account number situation?

Answer 1

If ik_pm_no is an account number in the sense of an invoice serial number (most likely, it seems to me) - then what does the user have to do with it? The user should not enter anything,
you should generate this number on the server side each time the page with the form is generated and put it in the database along with the rest of the form parameters.
And for each invoice to store the status - whether it is paid or not.
@Dimitriys wrote everything correctly.