To make your hotspot a hidden network, you can follow the below steps:
1. Go to the settings app on your iPhone/iPad and select Personal Hotspot.
2. Toggle on the Personal Hotspot switch.
3. Click on Wi-Fi Password and create a secure password.
4. Click on the Wi-Fi icon located next to Personal Hotspot and click on configure hotspot.
5. Scroll down and toggle on the "Hide My Network" option.
This will make your hotspot invisible to other devices unless they know the exact name of your network and password. It is important to note that hiding your network doesn't provide complete security and some devices may still be able to detect it if they have the right tools.