IPhone XR failing to focus

• Learn iPhone camera basics - Apple Support
• Understand About the Camera features on your iPhone - Apple Support (IN)
• Take appropriate action to Adjust HDR camera settings on iPhone - Apple Support (IN)
• You may Use camera modes on your iPhone, iPad, and iPod touch
• Learn how to --> Take Portrait mode photos with your iPhone camera
• Try to Change advanced camera settings on iPhone - Apple Support
• For Slow Motion and Trimming --> Trim video length and adjust slow motion on iPhone
• Here you can see an Apple Article with all video recording options --> Record videos with your iPhone camera - Apple Support

I take tips from here too. --> Tutorials | iPhone Photography School

Broken or contaminated.

Take it in for a repair estimate but be prepared for $hundreds