How to activate the camera without touching the screen?

I would like to activate the camera without having the touch the screen. Recently switch from android and missing the double click power functionality to activate the camera. In glove weather and with doing farm work touch gloves are not appropriate for the type of work. I know there is siri, but sometimes the best moments you want to capture you would prefer not to interrupt by asking the camera to activate. I explored the back tap functionality however camera is not a default option, and beside if it added via a custom shortcut the screen needs to be fully unlocked for the back tap to function. I would love a way to button activate the camera, anyone know how to set this up?