Open the Camera application.
Press the Live Photo icon in the photo interface to disable it. In iOS 16, it is situated in the upper right.
That's it. When you open your Camera app again, the Live Photo icon ought to be disabled.
Pressing the symbol will turn on Live Photos once more, and with this setting selected, it will remain on until you decide to turn it off.
The iOS photography experience includes cool but inessential Live Photos, which record the seconds just before and after you take a photo, including audio.
They're terrific for producing your own GIFs from images and for "bringing to life" specific photos, but they also use a lot of storage space.
Typically, the files are twice as large as those for a typical photo. Given that Apple leaves Live Photos turned on by default, this could be a concern for your photo storage.