Is it permissible to perform Salat al-Gha'ib individually for someone who died of Corona and was not washed, buried, or prayed over with the funeral prayer as required?

Firstly: The funeral prayer for the absent (Salat al-Gha'ib) is legislated for a deceased person who has not been prayed over in their own land, just as the Prophet prayed over the Negus. This is because he died among disbelievers and was not prayed over. If he was prayed over where he died, then the funeral prayer for the absent is not legislated. What some people do, praying every day for all Muslims who have died, is an innovation.

Secondly: The principle is that the funeral prayer (Salat al-Janazah) is performed in the presence of the body. However, if presence is difficult due to hardship or prohibition, as in the case of an epidemic, then the funeral prayer for the absent is legislated, provided that no one has prayed over the deceased. Otherwise, the funeral prayer for the absent is not legislated.

Thirdly: The funeral prayer is valid if performed by an individual; congregational prayer is not a condition for it.

Fourthly: The deceased is prayed over after being washed. However, if washing is difficult due to an insurmountable reason, then the legislation of praying over them is not negated.