Xen. A 1 4.9

Xen. A 1 4.9

How do you conjugate σκηνόω and arrive at ἐσκήνουν (aor. 3 pl.?) ?
Ancient Greek Conjugator and Wiktionary are silent on that.

Wiktionary had εσκηνωσεν - Verb, aor. act. indic. 3s.

Imperfect, not aorist.

Thanks. Forgot about o-contract.