Generating and Exporting a HAR File in Mozilla Firefox - Generating-HAR-files-for-Support-Cases/Generating-and-Exporting-a-HAR-File-in-Mozilla-Firefox

Select More Tools > Web Developer Tools and then select Network.

Refresh the page to capture the traffic between the browser and the server.

Attempt to reproduce the issue.

Click in the grid of network traffic and select Save All As HAR. Alternatively, you can select the settings icon to save the HAR file.