How can I update my phone

Hello vihan274!

Assuming you're wanting to update to iOS 16, please check Here to see if your device is compatible (with iOS 16.)

If you are referring to something else, here’s how to Update your iPhone or iPad - Apple Support.

If you can't update or restore your iPhone or iPod touch - Apple Support, you may find this link of assistance.

I hope this is helpful. Good Luck!