Yes, you can reverse charge on iPhone 11. To do this, follow these steps:
1. Connect your iPhone 11 to a power source using a USB-C to Lightning cable.
2. Press and hold the Side button and either volume button until the power off slider appears.
3. Drag the slider to the right to power off your iPhone.
4. After your iPhone 11 has powered off, press and hold the Side button again to turn on your iPhone.
5. When you see the Apple logo, release the Side button.
6. On the Lock screen, you should see "Charging with USB" and a battery icon next to it. This means that your iPhone is now charging wirelessly.