What is the ruling on supplicating for or giving charity on behalf of everyone who watched or published a clip on social media, and does the reward reach everyone who watched or published it?

It is permissible to supplicate for others, even if the supplication is conditional upon a specific action. Supplications related to specific actions have been mentioned in the Prophetic Sunnah (definition). It is also permissible to include others in the reward of charity, whether the charity is intended for Muslims in general or is made conditional. The reward reaches those for whom the supplication is made or on whose behalf the charity is given, without any decrease in the reward of the one giving charity.