Allah's Messenger (ﷺ) made it incumbent on all the slave or free Muslims, male or female, to pay one Sa' of dates or barley as Zakat-ul-Fitr.
Sahih al-Bukhari Book 24, Hadith 104
← Previous Hadith Allah's Messenger (ﷺ) enjoined the payment of one Sa' of dates or one Sa' of barley as Zakat-ul-Fitr on every Muslim slave or free, male or female, young or old, and he ordered that it be paid before the people went out to offer the `Id prayer. (One Sa' = 3 Kilograms approx.)

Sahih al-Bukhari Book 24, Hadith 103 Next Hadith → We used to give one Sa' of barley as Sadaqat-ul-Fitr (per head).

Sahih al-Bukhari Book 24, Hadith 105