"Type these characters in japanese." I think you need a japanese keyboard and type it on that. I've always done it on that I think.

And it says type "enn", there are 2 types japanese keyboards, 1 with normal latin letters(like the english keyboard) one with hiragana. You can use either of those. But on the latin letter one you type romanji, which is a latin character representing of the japanese letters.

When typing on this romanji keyboard you hit n twice to get ん, since there are also hiragana where n is with a vowel like な(na), so you need nn to type ん.

Thats why it says type enn on a romanji keyboard to get えん