All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
According to the view of the majority of the scholars, it is a condition that the Kafaarah (expiation) be given to the Muslims.
Nonetheless, Abu Haneefah permitted it to be given to a poor Thimmi (a non-Muslim resident in the Muslim state under the Muslims’ protection according to an agreement). However, the view of the majority of the scholars is better in order to be on the safe side.
The Fiqh Encyclopedia reads when clarifying the conditions to whom the expiation should be paid:
“B- They must be Muslims: it is not permissible according to the view of the majority of the scholars to feed a non-Muslim from the expiations whether he is a Thimmi or belligerent non-Muslim, but Abu Haneefah and Muhammad [who is his Companion] permitted that the Thimmis be given expiations for the general Saying of Allah (which means): {So its expiation is the feeding of ten needy people.} [Quran 5:89], without any distinction between a Muslim and a non-Muslim.
For more benefit, please refer to Fataawa 348907, 241990, and 50362.
Allah knows best.