13pro back camera not working

Did you already try to force restart your iPhone 13Pro?

Force restart iPhone - Apple Support

If this does not bring back the camera function, the next step would be setting the phone back to factory settings without using the latest backup, and setting it up as a new device. That way you can rule out a software issue:

How to factory reset your iPhone, iPad, or iPod touch - Apple Support

Restore your iPhone, iPad, or iPod to factory settings using a computer - Apple Support

If the camera does not work after that, this looks like a hardware issue and the iPhone has to be serviced:

Apple - Support - iPhone Repair and Service

Welcome and thank you for reaching out. 🤗

There appears to be a problem with the camera and/or related sensors. Only a certified Apple technician can determine the cause and offer a complete solution.

Therefore, I recommend service.

Service Checklist:

• iPhone service pricing.
• Check AppleCare Coverage.
• Get your iPhone ready for service.

Service Appointment:

• Get started with camera service.

Contact Information:

• United States: 1-800-APLCARE.
• Contact Support.

Additional Support:

• iPhone Support.
• iPhone User Guide.
• Check Repair Status.

Good luck! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer

You can contact Apple Support to run diagnostics and check if iPhone reports some hardware issues.

if the camera is black in multiple apps, it can be the camera hardware.