Apple introduced third-party keyboard back into iOS 8, and sweep feed options like Gboard, SwiftKey and Swype made it easier to write on an iPhone. Even better, apps like the Word Flow keyboard moved to the side of the iPhone so that there was less tumble stretching. Well, now Apple has its own option in iOS 11 and iOS 12 for better hand management in the stock keyboard.
To use one-of-a-kind mode in Apple's default keyboard, make sure you run at least iOS 11 on your iPhone, so it works in IOS 12. Even before continuing, it's worth noting that this only works in portrait orientation.
When using the Apple keyboard, long press the icon next to the "123" button (on older iPhones) or the bottom-long corner of the screen (on Face ID iPhones) to bring up the keyboard menu.
If you have no third-party keyboard installed or additional languages from Apple enabled, you'll see a smiley emoji instead of a globe. For those of you who do not see a globe or smiley there, it's because you do not even have the Emoji keyboard enabled for any odd cause.
To clarify, you can not use Apple's single keyboard unless you have either the Emoji keyboard, another language keyboard, or a third-party keyboard also enabled. You need at least one additional keyboard except "English (USA)" or what your primary language is.
After pressing the ground or smiley, under the list of enabled keyboards, you can switch to see left, center, and right icons for Apple's stock keyboard. If you use your iPhone with your left hand, select left orientation. If you use your iPhone to the right, choose the correct orientation.
Whenever you want to return to the middle mode, simply press the arrow opposite to the left or right-hand keyboard to expand it to full width. These options work for any of Apple's available "iPhone Keyboards".
However, note that if you are currently using the Emoji keyboard, you will see either an ellipsis (•••) or "ABC" icon where the world or smiley were, but long-term pressing both options also opens the keyboard's setup panel.