An example of how you can use the facebook api to populate a google sheet.

facebook-ad-insights.gs

// https://www.benlcollins.com/apps-script/api-tutorial-for-beginners/
function main() {
  let accessToken =  "YOUR_ACCESS_TOKEN"
  let fields = "account_id,account_name,date_start,date_stop,impressions,spend"
  let accountIds = getAccountIds(accessToken)
  let jsonData = getAdInsights(accountIds, fields, accessToken)
  let sheet = SpreadsheetApp.getActiveSheet()
  let dataKeys = Object.keys(jsonData[0])
  let dataArray = convertToArray(dataKeys, jsonData)
  dataArray.unshift(dataKeys)
  let range = sheet.getRange(1,1, dataArray.length, dataKeys.length)
  range.setValues(dataArray)
}

function convertToArray(dataKeys, jsonData) {
  Logger.log(dataKeys)
  return jsonData.map(entry => {
    Logger.log(entry)
    return dataKeys.map(key => entry[key])
  })
}

function fbRequestJsonData(url) {
  var response = UrlFetchApp.fetch(url)
  if (response.getResponseCode() != 200) {
    throw `ERROR: Failed to make request ${url}, response code:` + response.getResponseCode()
  }
  return JSON.parse(response.getContentText()).data
}

// https://developers.facebook.com/docs/marketing-api/connectionobjects/v11.0
function getAccountIds(accessToken) {
  return fbRequestJsonData(`https://graph.facebook.com/v11.0/me/adaccounts?access_token=${accessToken}`).map(account =>{
    return account.id
  })
}

// https://developers.facebook.com/docs/marketing-api/insights/
function getAdInsights(accountIds, fields, accessToken) {
  return accountIds.flatMap(id => {
    return fbRequestJsonData(`https://graph.facebook.com/v11.0/${id}/insights?access_token=${accessToken}&fields=${fields}`)
  })
}