Google sheet : quickly replace CRYPTOFINANCE

Code.gs

// use as before: e.g. CRYPTOFINANCE("XLM/USD")
// there's no way to use CRYPTOFINANCE("BINANCE:XLM/USD") without a paid account, so I didn't implement it
const API_KEY = 'YOUR_COINMARKETCAP_API_KEY' // do not forget to replace it with your own API key ;)
const domain = 'https://pro-api.coinmarketcap.com';
const ticker = 'v1/cryptocurrency/quotes/latest';
const options = {
  method: 'GET',
  headers: {
    'X-CMC_PRO_API_KEY': API_KEY,
  }
};
function CRYPTOFINANCE (PAIR) {
  const [BASE, QUOTE] = PAIR.split('/')
  const uri = domain + '/' + ticker
  const symbol = 'symbol=' + BASE
  const convert = 'convert=' + QUOTE
  const url = uri + '?' + symbol + '&' + convert
  const response = UrlFetchApp.fetch(url, options)
  const json = JSON.parse(response)
  const price = json.data[BASE].quote[QUOTE].price
  return price
}