Which parameters are needed while creating the one-time link?

Mobile number is a mandatory parameter that will take the user to the home page.

If a category Code is passed, it will show the user the list of Billers.

If the category code and the biller ID are passed, it will show the bill fetch form.

If the category code, biller Id, and customer parameters are passed, it will show the bill directly. The session is valid only for some time and becomes invalid if the user is inactive. You would need to generate this link uniquely for each of your customers and make sure you get a new link each time your customer wants to get back to the bill payment journey.