It includes both men and women. And it’s not a compulsion. It’s a recommendation. Here is a hadith in Makarem al-Akhlaaq:
في (مكارم الأخلاق) عن الصادق (عليه السلام) قال: قال رسول الله (صلى الله عليه وآله): أنهى أمتي عن التختم في السبابة والوسطى.
The Prophet (s) said: I prohibit my Ummah from wearing a ring in the middle and index fingers.
And the word Ummah includes men and women.