لَا تَرْضَ — لَا تُرْضَ
Translation: Do not be pleased — let it not be approved of (passive construction).
PersonActive prohibitionPassive prohibition
2m sgلَا تَرْضَلَا تُرْضَ
2m dualلَا تَرْضَيَالَا تُرْضَيَا
2m pluralلَا تَرْضَوْالَا تُرْضَوْا
2f sgلَا تَرْضَيْلَا تُرْضَيْ
The prefix vowel distinguishes voice. Prohibitive lā makes the imperfect jussive, not merely negative. The passive wording is grammatical but not necessarily idiomatic in an everyday command.