IGV must be running on your computer before clicking the button.

If your browser shows the "cannot open the page" error, launch IGV and allow access via port 60151:

1. Open IGV on your computer
2. In IGV's menu bar: View → Preferences…
3. Click on the "Advanced" tab
4. Check "Enable port"
5. Set the port number to 60151
6. Click OK to save

For more details, please refer to Information → FAQ.