When installing the Highfive application using Safari on macOS, a prompt should appear at the top of your Safari web browser window. This asks you to Trust the Highfive Launcher plug-in.

If you are not seeing the Trust pop-up, as expected, follow the steps below:

1. Fully quit the Safari web browser window. You can either:
    - Press ⌘ + Q on your keyboard.
    - Click Safari in the top-lefthand corner of your desktop and select Quit Safari.
    - Right-click on the Safari icon in your Dock and select Quit.
2. Launch Safari again and then go to https://start.highfive.com to retry the installation process.
3. Highfive! Safari will now be able to open the Highfive application automatically.

If the issue persists, make sure the Highfive Launcher plug-in is enabled in your Safari Preferences:

1. Click Safari in the top-lefthand corner of your desktop.
2. Select Preferences.
3. Select the Security tab.
4. Select Plug-in Settings...
5. Search for the Highfive Launcher plug-in and select it.
6. In the bottom-righthand corner, make sure the "When visiting other websites" setting is On.
7. Go to https://start.highfive.com.
8. Highfive! Safari will now be able to open the Highfive application automatically.

If you continue to experience Highfive application installation issues, please contact Highfive Support at help@highfive.com or (844) 464-4445 through the hours of 7am-5pm Pacific Time on weekdays.