How do I switch between an enter/emoji key on my Microsoft SwiftKey Keyboard?

With Microsoft SwiftKey you have the option to choose between having a default enter (return) or emoji key. To edit this setting:

1. Open the Microsoft SwiftKey app
2. Tap 'Emoji'
3. Toggle the 'Dedicated emoji key' setting to the on position

When this option is left unchecked, emoji can still be accessed from within your messaging apps by long pressing the enter key.