iOS story board image referencing issue

Using Unity 2019.3+ I see there is no option to set legacy launch screens anymore. The only suitable versions seems to set a custom storyboard, but there is no guide anywhere how to set it properly.

The idea is to set start screen same as my 1st app screen background image. This image path is Assets/Textures/LoginScreen.png.
Creating custom storyboard in XCode I need to reference this image somehow, but how can I do it properly? Is there any specific path I need to place the image in Unity project so the referenced .storyboard file in player settings will find that image? Also, pretty important to avoid duplicating the image, because it takes much space.