arsToUsd.js

const regex = /^(\d*([.,](?=\d{3}))?\d+)+((?!\2)[.,]\d\d)?$/

const dollar = await fetch('https://api.bluelytics.com.ar/v2/latest')
     .then(res => res.json())
     .then(data => data.blue.value_sell)
     .catch(err => console.log(err))

document.querySelectorAll('*').forEach((node) => {
     const word = node.textContent.split(' ')
     const isPrice = regex.test(word) && word > 0

     if (isPrice) {
          const valueInArs = Number(word[0].split('.').join(''))

          const formattedNumber = (valueInArs / dollar).toFixed(2)

          node.textContent = formattedNumber
     }
})