I am working on a website which provides an online option for mobile refill, Where customer can enter the amount to be recharged.
If we use simple product for it and use the custom option as text field, is it possible to change the amount of product as per the amount entered.
I tried to find the relative extension but was not able to get any. Is there any extension which fulfills such requirement ?
It would be great if anyone can guide me from where to start.