Within the JetStream Client 

  1. Navigate to the top right-hand side and select the gear icon.
  2. Scroll down to the Troubleshooting section and the default path will be displayed.

Note: Click on the default path will open in your respective operating system's file browser

Default Windows location: C:\Users\user\AppData\Local\GoJetStream\logs

Default MacOS location: /Users/user/Library/Application Support/GoJetStream/log