Update

You should be able to update an iPhone 11 to iOS 13 immediately.

iOS 13 and iPadOS are compatible with these devices - Apple Support

Update your iPhone, iPad, or iPod touch - Apple Support

Are you having a problem you can describe in more detail?

yvonnefromdenver wrote:

When will I be able to update my iPhone 11 to iOS 13?

Well, at the moment we have iOS 13.5.1 and you can only update to that version.

iOS 13 is gone.

your profile shows that you are already on iOS 13