Is there an example code to open an fullscreen window in ipad?

Hello,

I can open an 320x480 window with SDL2 and that works correctly on
ipad. But what I can see is a black screen on ipad if I try open a
1024x768 window. And the 1024x768 window with
SDL_WINDOW_FULLSCREEN|SDL_WINDOW_BORDERLESS also failed.

On the other hand, displaymode.w = 320 and displaymode.h=480 if we
call SDL_GetDesktopDisplayMode(0, &displaymode).

Is there any sample code that can open a fullscreen window with full
resolution (1024x768) for ipad? Thanks!

Best regards,