[1] Dinka: History, Religious Systems, and Rituals https://link.springer.com/rwe/10.1007/978-94-024-2068-5_104

[2] Perspectives on Lozi traditions. https://repository.up.ac.za/bitstreams/cca7ee20-46fa-4585-b1...

Ancient China had a monotheistic religion where they worshiped Shang Di, a monotheistic God without idols, who could not be drawn, and they made yearly sacrifices to at a single Temple.

There are schools that say Hinduism is monotheistic, where Para Brahma is God, and the different "Gods" like Shiva and Vishnu are different avatars of Para Brahma. But there are a lot of schools/philosophies of Hinduism and I only have a surface level understanding.