What if you don’t have enough storage space for updates

You can try updating using a computer, that method doesn't require as much free space on your phone.

If you still need more space -

Here are some helpful articles that can guide you on how to free up storage space on your phone.

How to check the storage on your iPhone, iPad, and iPod touch

https://support.apple.com/en-us/HT201656

Manage your photo and video storage

https://support.apple.com/en-us/HT205703

Clear Other storage on your iPhone or iPad

https://support.apple.com/en-us/HT211686

Update using your computer -

https://support.apple.com/guide/iphone/update-ios-iph3e504502/ios