BibTeX:
@incollection{Various,
  author = {Various},
  title = {Tabriz, July 1850: Anís accompanies the Báb in facing the firing squad},
  booktitle = {Baha'i Stories Blog},
  url = {https://bahaistories.blogspot.com/2018/06/tabriz-july-1850-how-anis-became.html},
}

APA:
Various. Tabriz, July 1850: Anís accompanies the Báb in facing the firing squad. In *Baha'i Stories Blog*.

MLA:
Various. "Tabriz, July 1850: Anís accompanies the Báb in facing the firing squad." *Baha'i Stories Blog*, n.d..

Chicago:
Various. "Tabriz, July 1850: Anís accompanies the Báb in facing the firing squad." In *Baha'i Stories Blog*, n.d..