iPhone F.lux on iPhone 12 Pro

[MacBainNO]

I got the new iPhone 12 Pro and miss f.lux. I used it on my iPhone 7 Plus and my iPad Air 2.
But, it won't work on the 12 Pro.
I use the sideload method and xcode and it still works flawlessly when I transfer the app to the previous devices.
I don't get any errors when I transfer the app to the iPhone 12, but when I try to run the app it just freezes at the f.lux logo screen.

Any idea on how I can get this to work?

 

[one more]

I use flu.x on a MacBook, but find it unnecessary on either iPhone or iPad, as I find that True Tone and Night Shift combo in iOS/iPadOS do an excellent job, IMO.

 

[MacBainNO]

I use flu.x on a MacBook, but find it unnecessary on either iPhone or iPad, as I find that True Tone and Night Shift combo in iOS/iPadOS do an excellent job, IMO.

I find f.lux way superior then both of these, but maybe it's just because I'm used to them. Still would like to get it to work