How to fix 'TypeError: Cannot read property 'map' of undefined' when using Axios to fetch data from an API in ReactJS?

when getting req from API .. res => this enter image description here

when added to my project like that enter image description here

send me this error enter image description here

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>Solution :

Assuming you’re getting the response in a variable called res such that:

let res = {
  "prices" : {
    "BTC/USDT" : 27071.28
  },
  "ms" : 3
}

Then to get prices you can use: res.["prices"].["BTC/USDT"]

So here at line 40 you can use const req = '${btcToUsd}.["BTC/USDT"]'