Is it permissible to perform congregational or Friday prayers via live broadcast (television or social media), and would the worshiper be credited with the reward of congregational or Friday prayers in this case?

It is not permissible to follow the Imam via television, whether in normal circumstances or in times of necessity, and the desire to gain reward is not a justification. As for one who is excused from going to the mosque due to an epidemic or similar reason, his share of the reward for congregational prayers and Friday prayers is preserved even if he prays alone in his home. Indeed, whoever is prevented from an act of obedience that he was accustomed to or intended to perform, its full reward will be written for him.