Ionic - images not showing in web/android/ios


I have an issue with images in Ionic 3. They are not showing properly in webapp, android and iOS.
After reading a lot about this, I’ve put all of this images into assets folder, in imgs subfolder. When showing pictures from .html files I’ve linked them as assets/imgs/logo.png, and from the .ts files as ../assets/imgs/logo.png.
Now, this worked for pictures in webapp and Android, but not for iOS (alt was showing there), but pictures linked in .ts files are not showing at all.

So, can anyone help me to solved this once and for all?
My questions are:

  1. Where should I keep images?
  2. How should I link images in .html and how in .ts files?
  3. How should I link images for different platforms, and what is universal linking way to make it work in webapp, Android and iOS?