What is the ruling on giving charity via mobile phone by sending a blank message to a specific number provided by the telecommunications company, and is it considered charity?

The باب (door/gateway) of charity is wide, and the paths of good are many. There is no شرعي (Shar'i/Islamic legal) prohibition against giving charity by sending messages. If the giver of charity intends it as such, they will receive its reward. However, one should verify that the entity collecting the funds spends them in their شرعية (Shar'i/Islamic legal) channels and delivers them to those who are entitled to them.