The updated iPhone camera app in iOS 14 has changed some settings or added new ones. If you want to take square photos, see how you can do it.

Open the "Camera" application. Swipe up anywhere on the screen or tap the arrow icon at the top of the screen. This displays all the extras choices at the bottom of the "viewfinder".
Press "4: 3" (this is the default cut of the iPhone camera).
Press "Square" to toggle from 4: 3 mode to square.
Are you ready! Now you can take out square photos.
If you want to shoot wider, 16: 9 movies, you can select "16: 9" from the same menu.
Crop photos after
Taking square photos already cuts your images. Your iPhone still stores the full file, so you can return to the original 4: 3 image at any time. Or you can crop any existing image into a square. See how.
Open the image you want to crop in the Photos app. Click "Edit" and then icon pruning.
Then click on the proportions icon dimensions and select the option you want.
You can drag the edges of the tool pruning to change the framing of your image. When you are happy, press "Done" to save the results.
Η Photos application is full of photo editing capabilities that you can find by searching the app.
Source: zdnet.com