Generate a HAR File in Your Browser

To generate a HAR file in Google Chrome and Microsoft Edge (Chromium Based)

Look for a round record button in the upper left corner of the tab, and make sure it's red. If it is grey, click on it to start the Network recording log (Ctrl+E).
Click the Clear button to clear out any existing logs from the Network tab.
Reproduce the issue that you were experiencing, under the Name column right-click on any network request within the grid, and select Save all as HAR with Content.
Select Desktop, then click the Save button.

To generate a HAR file in Mozilla Firefox

Open Firefox and go to the page on which you are experiencing the issue.
Select the Firefox menu at the top-right of your browser window, then select More Tools > Web Developer Tools
The Developer Network Tools opens as a panel at the side or bottom of Firefox. Click the Network tab.

Check the Persist Logs box by clicking the gear icon in the top right corner.

Reproduce the activity that was causing the issue in the browser, then right-click anywhere within the grid of network requests, and select Save All As HAR.
Right-click on any network request within the grid, select Save all as HAR with Content,
Select Desktop, then click the Save button.

To generate a HAR file in Apple Safari

Click on the Develop drop-down menu, and then select Show Web Inspector.
- If you don’t see the Develop drop-down menu in the menu bar, choose Safari > Preferences, click Advanced, then select the Show Develop menu in menu bar.
Check the box next to the Preserve Log.
Click the Network tab and reproduce the activity that is causing issues.
Click the export icon, and then save the web archive file to your desktop.

Thanks for your feedback.