BibTeX:
@incollection{Various,
  author = {Various},
  title = {Baha'u'llah - The King of Kings},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2019/10/bahaullah-king-of-kings.html},
}

APA:
Various. Baha'u'llah - The King of Kings. In *Baha'i Stories for Children*.

MLA:
Various. "Baha'u'llah - The King of Kings." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "Baha'u'llah - The King of Kings." In *Baha'i Stories for Children*, n.d..