How to update my phone

Assuming a compatible device, see: Update your iPhone, iPad, or iPod touch - Apple Support

hi there

to update your device wirelessly follow these steps: 

1. Plug your device into a power source and connect to the Internet with Wi-Fi.
2. Go to Settings > General, then tap Software Update.
3. 
4. 
   
5. Tap Download and Install. If a message asks to temporarily remove apps because the software needs more space for the update, tap Continue or Cancel. Later, iOS or iPadOS will reinstall apps that it removed. If you tap Cancel, find out what to do next.
6. To update now, tap Install. Or you can tap Later and choose Install Tonight or Remind Me Later. If you tap Install Tonight, just plug your device into a power source before you go to sleep. Your device will update automatically overnight.
7. If asked, enter your passcode. If you don't know your passcode, find out what to do.

hopefully this helps and if you have further questions don't hesitate to reply to this thread

regards, francesco