The Behringer Go MIDI Host is an excellent OTG solution for USB to MIDI DIN in/out conversion,and power for a MIDI controller keyboard/pad etc, all in one compact box,
It's purpose is freedom to connect direct or daisy chain to other MIDI devices, whilst remaining independent of the usual pc/tablet/app DAW hookups for power
The Host uses 2 x USB type C input sockets for the power in and controller cable, and it uses 2 x standard 5 pin DIN sockets for MIDI in/out connectivity