How to make return key for extension keyboard

I made a custom keyboard.

However, I'm not sure how to actively create buttons according to the input type like the iPhone's default keyboard.

This is the information I found.

typedef enum {
case 'default'


case asciiCapble


case numberAndPunctuation


case URL

case numberPad

case phonePad

case namePhonePad

case eamilAddress

case decimalPad

case twitter

case webSearch

case asciiCapbleNumberPad
}UIKeyboardType;
static var alphabey: UIKeyboardType
Specifies a keybovard optimized for alphabetic entry