Is it possible to turn on the iris recognition infrared LED and take photos using the front camera, that works on the Galaxy S9+?
In the YouTube video: "Poco F1 Infrared Camera Hack - How to take photos with the Infrared Camera" they mention a Google Play Store application: "MIUI Hidden Settings" that allows you to turn on the iris recognition LED and activate the front camera at the same time - the only limitation is that to take a photo you need to take a screenshot, with resulting lower resolution. That APP doesn't work on the Galaxy S9+.
I found a similar question: "Is there an Infrared camera app?" at XDA. There's a somewhat similar question here called: "Controlling IR in Galaxy S8?" but it seems limited to turning on the IR LED (which might be enough) and doesn't mention IR photography which is what I want.
The results, if you can get it working on your phone, seem reasonable:
(Tap to enlarge)
I even tried dialing the hardware test number
*#0*# but the phone doesn't allow screenshots, nor is the image very large or illuminated. If there is another test number or a means to trick the hardware I can't find it, if there is a particular APP it is likely rare and the only one available.