“English (US, International with dead keys)” missing on Ubuntu 18.04

The menu with the keyboard-layouts is bit hidden in Gnome. To set your keyboard-layout open language-settings and click the Plus-Button(+) at the bottom left. Than add your language again and after that the sub-menu with the keyboard-layouts will open.

The full path to reaching the option is: Settings app -> Region & Language -> Click the + icon in Input Sources -> Select your main language -> Select the keyboard layout from the sub-menu