See request time in Chrome developer tools

You just need to click on the request row:

Right Click > Copy > Copy All as HAR

Then open the HAR file:

{
  "log": {
    "version": "1.2",
    "creator": {
      "name": "WebInspector",
      "version": "537.36"
    },
    "pages": [],
    "entries": [
      {
        "startedDateTime": "2018-08-24T18:34:12.564Z",
        "time": 84.96354891383089,

There is the exact request timing info.