How to download 11.0 iOS?

On what device, running what iOS version?

Your signature suggests you have iPad running iOS 10, which likely means you have iPad 4, which cannot be upgraded beyond iOS 10.3.x. If you need the newer iOS versions, you'll need to buy a newer more modern device.

You can't. An iPad 4 isn't capable of it, and any newer model can only be updated directly to 12.5.3, 14.6, or higher betas for people enrolled in one of Apple's programs.

(199719)

Go to Settings > General > and update will show you and update to the latest iOS version your iPhone can handle.