iphone stuck on recovery mode

If you have backup then you can restore from it,

If you can't update or restore your iPhone, iPad, or iPod touch

You can put your iOS device in recovery mode, then restore it with iTunes.

In these situations, you might need to use recovery mode to restore your device:

• iTunes doesn't recognize your device or says it's in recovery mode.
• If your screen is stuck on the Apple logo for several minutes with no progress bar.
• You see the connect to iTunes screen.

Learn what to do if you see the progress bar on your screen for several minutes.

Put your device in recovery mode and set it up again

1. Make sure that you're using the latest version of iTunes. 
2. If iTunes is already open, close it. Connect your device to your computer and open iTunes. If you don't have a computer, borrow one from a friend or go to an Apple Retail Store or Apple Authorized Service Provider for help.
3. While your device is connected, follow these steps: 

• • iPad models with Face ID: Press and hold the Top button and either volume button until the power-off slider appears. Drag the slider to turn off your device. Connect your device to your computer while holding the Top button. Keep holding the Top button until you see the recovery-mode screen.
  • iPhone 8 or later: Press and hold the Side button and one of the volume buttons until the power-off slider appears. Drag the slider to turn off your device. Connect your device to your computer while holding the Side button. Keep holding the Side button until you see the recovery-mode screen.
  • iPhone 7, iPhone 7 Plus, and iPod touch (7th generation): Press and hold the Side (or Top) button until the power-off slider appears. Drag the slider to turn off your device. Connect your device to your computer while holding the Volume Down button. Keep holding the Volume Down button until you see the recovery-mode screen.
• iPad with Home button, iPhone 6s or earlier, and iPod touch (6th generation) or earlier: Press and hold the Side (or Top) button until the power-off slider appears. Drag the slider to turn off your device. Connect your device to your computer while holding the Home button. Keep holding the Home button until you see the recovery-mode screen.
  • 

1. When you see the option to Restore or Update, choose Update. iTunes will try to reinstall iOS without erasing your data. Wait while iTunes downloads the software for your device. If the download takes more than 15 minutes and your device exits the connect to iTunes screen, let the download finish, then repeat step 3.
2. 
3. After the Update or Restore completes, set up your device.

If you can't update or restore your iPhone, iPad, or iPod touch - Apple ...

https://support.apple.com/en-us/HT201263