Is it permissible to donate to non-profit educational platforms, managed by non-Muslims, to ensure their continuity and remove advertisements from them?

It is permissible to donate to a platform whose content is free from শরীʿআ (Sharia) prohibitions, even if those in charge of it are non-Muslims. Jurists have explicitly stated the permissibility of giving gifts, presents, and charity to a disbeliever, and there is no difference whether the recipient of the donation is an individual, an institution, or a legal entity.