A4 MIDI Clock Out Via USB

Has anyone had any success taking a MIDI clock from the A4 to other gear? I’m trying to sync Lemur on an iPad to my A4 using the camera connection adaptor and data seems to just flow one way (from the iPad to the A4).

ive successfully sent midi to an ipad via usb. not sure if all apps support it or not. in the app there was a setting that allowed me to choose the sync source