The iPhone’s camera app automatically turns on the Night Mode when it detects low light. When Night Mode is on, the camera doesn’t use flash and uses long exposure to capture photos. Sometimes it becomes annoying because you actually want to use flash, not the night mode. Although the camera app uses Night Mode automatically, it has an option to disable the Night mode if you don’t want to.
Turn Off Night Mode in Camera on iPhone
When you don’t want to use the Night mode, click on the Night mode icon at the top left corner. Tap on it and it will turn off the Night mode.

In iPhone models running iOS 15 or older versions, It will open a slider at the bottom side of the camera viewfinder. Here, drag the slider to left most side to turn off the Night Mode.
It will turn off the Night mode and you can capture photos normally. If you drag the slider to the right side, it will enable the Night mode and increase the shutter speed.
If you don’t want to turn off Night Mode each time, you can keep it off until you manually turn it off. For this, you need to Preserve Night Mode settings. Follow the steps given below for this.
Open the Settings app on your iPhone and scroll down to ‘Camera’. Here, Tap on ‘Preserve Settings’ and Toggle on Night Mode

It will remember your Night Mode setting. If you have turned it off, it will remain off until you enable Night Mode manually in the camera app.
This is how you turn off the Night Mode in the iPhone camera app. Now the app will not automatically enable the Night Mode until you do it manually.