A grid of horizontal images

I’m trying to get DALLE 3 to generate a grid of horizontal images but instead it keeps generating grids in which the images develop vertically. I tried to specify this several times in the prompt and also to tell him that I want the individual images in the grid to be, for example, in 16:9 format or at least horizontal but there is no way I can get what I need.
Does anyone know how to help me? A thousand thanks