What is in a HAR file?
HAR is an abbreviation of 'HTTP Archive'. It is a file containing a log of trace information from within a browser session. It records web requests made by the browser to the website page including request and response headers, the body, and the time it takes to load the assets.
Why would we want this information?
As we want to know more information about the network and the error about the said issue.
Network activity and HAR file
HAR file is preferred, but if not, screen capture of the 'Network' tab (Plus text copy of the specific lines) can be used.