Audio input for iPhone 6s

I would like to insert line audio into my iPhone 6s. I have a lightning port connector, which has a TRRS female connector. I then i have plugged a TRRS male connector into this, and then various mono and stereo audio jacks into the microphone input end.

When recording on my camera app or instagram video, it does not record the audio from this line in. It only records audio from the phone's internal microphone.

In my system preferences I have set Instagram to have access to my microphone.

Please let me know how I can have Instagram or my Apple camera app record audio through a line-in device, and not through the phone's microphone (so that I can get better sound quality during recording videos).

Thank you.