hello guys,
A SOLUTION FOUND
Today I found an OTG cable that looks promising, although don’t think its original. When I plug it with my sound card, I got this message on the IPad “Cannot Use Device: M-Track: The connected device requires too much power” and that’s good news. At least the sound card is detected. So I bought Targus 4-port USB 3.0 hub with power adapter and try connect through it. That solved the problem. But I think I still need to get original OTG from apple. Don’t really trust this one although it works.
Thank you guys for your support.