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Your iPhone model has three lens. Which are, telephoto, wide, and ultra-wide as listed in the specifications of your device here: iPhone 12 Pro and 12 Pro Max - Technical Specifications - Apple
Just scroll down to the Camera section of the specifications. The three camera system (telephoto, wide and ultra-wide) allows you can take a picture at the regular length (wide) from your iPhone, one that’s zoomed-in (telephoto) or one that’s zoomed-out (ultra-wide). Each option can be selected while taking a photo or video. The resource you came from does explain how to use the Ultra Wide feature, which is one of the cameras:
About the Camera features on your iPhone - Apple Support
Review the section under "See beyond the frame". Other options are listed as 1x and 2.5x:
Use camera modes on your iPhone, iPad, and iPod touch - Apple Support
Take and edit photos on your iPhone, iPad, and iPod touch - Apple Support
Just incase, we'd like to share some additional resources that can help you get the most out of your camera:
Take videos with your iPhone camera - Apple Support
Change the camera’s video recording settings on iPhone - Apple Support
Adjust HDR camera settings on iPhone - Apple Support
If you require additional help, you might want to consider reaching out to Apple Support. You can use the link below to reach them:
Get Support
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