I can not scroll fully down to see my all contents

You used the wrong technique to create your nav menu.

Currently you have it set somewhere in the middle of the screen with constraints set to top.

You need to put it at the bottom of the scrollable content so it doesn’t cover it and set constraints to bottom.

can you pls describe little bit in detail

Another idea to try would be to apply a bottom padding on the scrollable container that is equal to the height of the bottom nav menu, assuming you have auto layout applied to the center content.