Is creating a religious account on social media platforms with the intention of making it an ongoing charity (sadaqah jariyah) and for spreading supplications (du'as), remembrances (adhkar), and religious topics considered a reward for its owner or an innovation (bid'ah), and must it be closed if there is no reward in it?

Creating accounts on social media platforms for the purpose of inviting people to Allah and encouraging good deeds is a great act of worship. It is a legitimate ongoing charity (Sadaqah Jariyah) as long as its benefit continues after death, provided that one is careful to select authentic Hadith and legitimate remembrances (Dhikr), and avoids innovations (Bid'ah) and weak Hadith.