Use the apostrophe spelling of the word

Error²Federal courts, Illinois courts21st and 22nd editions

Table T2's Japan page separates a syllabic n from a following vowel or y with an apostrophe, so the syllable break survives; a citation running the two together misspells the word.¹

1. 1T2.24 Japan.
2. 2An error: the rule in note 1 allows one form, and this is not it.