Go to your iPhone®/iPad®, open Settings -> Personal Hotspot -> Click the slider for “Allow others to join”
Log into you Pi-Star Dashboard and click on “Configuration”. Once on the configuration page scroll to the bottom of the page to the where you will see the "Wireless Configuration" section. Click Configure Wireless. When it refreshes, click Scan for Networks. Allow it about 10 or so seconds for the page to refresh and populate.
When it comes back up with the “Networks found” section, look for your iPhone®/iPad®. Click "Select" next to the SSID for your device. This will add a new SSID for your iPhone®/iPad®. Put in your password from the screen on the iPhone®/iPad® and click "Save and Connect".