I need help on an API

I have an API, which returns the value of bitcoin, now I want to get the quote of a value entered in an input, according to the current quote received via API, and convert this value into fractions of bitcoin ex: 0.0001 + my exchange rate commission earnings 15%, does anyone know if this is possible to do here?

As I understood , you are getting the value via API and then you want to display another value which is divided by a number and then add your commission rate… if this is correct … you only want to use a page variable with formula!