How do I change the lock screen wallpaper?

[Nirewen]

I just got this new LG K4 and it has Android 6 on it. I was customizing it yesterday and after finishing my home screen, I decided to change the lock screen. Tried changing its wallpaper in Settings, didn't work. Tried changing its wallpaper using Gallery, didn't work either. Then, I googled my problem to see if anyone has this before. I found a topic here saying what to do, tried many answers, none of them worked. Whenever I try, it changes my home screen's wallpaper, not lock screen's. Today I tried an app. A simple app. And it worked, the wallpaper changed. Kind of... The locked screen still has the same image, while the "put PIN" screen has the one I chose.

My lock screen is the one you can unlock using your face, by the way.

I don't have much to do other than ask if anyone had this problem before, and how managed to fix.

 

[ManiacJoe]

In Android 6 and below, there is no standardized way to set the lock screen wallpaper. If your phone does not directly allow for it in the settings app, some app developers figure out how to do it for some phone models, as you have already tried.

The higher-end phones from LG often allow for this in the settings app (not necessarily easy to find where), but I am not sure where the K4 ranks in that listing.