How to connect iPad and Hermod


What is the best way to connect an iPad with the Hermod to use all the midi sequencing possibilities of the iPad App ? is it even possible?
My hermod was set on a Doepfer minicase (alone) and my iPad was directly connected to the usb host of the hermod , I was using a midi app , PARAT +, trying to send some cc modulation to the hermod but it did not work. And the worst is that the power supply of the doepfer minicase did burnt and don’t work anymore.