Pressing on the shutter button changes only the volume on the iPhone#459

I’m trying to find the best shortcut to start up the Fjorden Camera app with the grip.

Ideally, I would like to take the iPhone out of my pocket, click on the camera grip and launch into the Fjorden camera app ready to take a photo.

However, all I get is changing the iPhone volume. Even if I have the iPhone unlocked, pressing on the grip’s shutter button does not launch the app so I need to follow a couple of steps:

Unlock iPhone.

Start the Fjorden app.

Start up the grip and then shoot a photo.

There must be an easier way and a shortcut I’m missing please let me know!