iPhone SE Camera not working

Have you tried any troubleshooting?

1. Restart: Press On/Off button until the Slide to Power Off slider appears, select Slide to Power Off and, after It shuts down, press the On/Off button until the Apple logo appears.
2. Reset: Press the Home and On/Off buttons at the same time and hold them until the Apple logo appears (about 10-15 seconds).
3. Restore: Connect your iPhone to iTunes on your computer, backup, and then select Restore to Factory.

If your iPod Touch, iPhone, or iPad is Broken

Apple does not usually fix iDevices except for screens and minor work they can do in their shop. Instead, they exchange yours for a refurbished or new replacement depending upon the age of your device and refurbished inventories. On rare occasions when there are no longer refurbished units for your older model, they may replace it with the next newer model. You may take your device to an Apple retailer for help or you may call Customer Service and arrange to send your device to Apple: You can make an appointment at the Apple Retail Store - Genius Bar and take it in for service. You can also look for an Apple Store - Find a Store - Apple. You will find respective repair costs in the appropriate link:

iPod Service Support and Costs

iPhone Service Support and Costs

iPad Service Support and Costs

Hi

If you have not yet done so, it may help to update your iPhone to the latest software, starting by making a backup:

Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support

Otherwise, follow the instructions here, including contacting Apple Support (mail-in service may be available, if required), making a Genius Bar reservation or visiting an Apple Authorised Service Provider if necessary:

Get help with the camera on your iPhone, iPad, or iPod touch - Apple Support