iOS
Turn OFF Airturn in iReal Pro.

RESET PAIRING: Pairing must be reset whenever switching from one device to another or when switching between MODES 1 and 2. With the PED powered on, press and hold the power button for six seconds. After two seconds, the PED will appear to power down. Continue to hold the power button. At six seconds both LEDs will blink three times. After the third blink release the power button. The device has been reset. Remove any old pairing from your host computer and then turn on the PED to pair again with desired host computer. (in your case, the iPad)

PAIRING: iOS – Select Settings>Bluetooth and turn on Bluetooth if it is off. When the PED is discovered, it will appear in the list of devices. Tap on the selection. A dialog box will then appear. Tap on Pair.

Make sure the PED is working if you go to another app like forScore, etc.

After that, open iReal Pro, turn on AirTurn and select the device there.

Note: In the AirTurn options in iReal Pro, try the Keyboard option in case the pedals are not working properly.