How do I create a HAR File?
Open Google Chrome.
Press Ctrl+Shift+I (Windows/Linux) or Cmd+Option+I (Mac) to open Chrome Developer Tools.
Make sure that the Preserve log option is enabled in the Network tab.
To start recording, click the round, gray recording button in the Network tab. If this button is gray, no recording is taking place. If the button is red, a recording is currently being created.
First, clear all previous activity by clicking the Clear button.
Reload the page where the problem occurred, then reproduce the problem.
To save the recorded data, right-click on the grid and select Save all as HAR with content.