BibTeX:
@incollection{Various,
  author = {Various},
  title = {From the time when the declaration was made to him at Baghdad Abbas},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/bahaullah-declaration},
}

APA:
Various. From the time when the declaration was made to him at Baghdad Abbas. In *bahaistories.com archive*.

MLA:
Various. "From the time when the declaration was made to him at Baghdad Abbas." *bahaistories.com archive*, n.d..

Chicago:
Various. "From the time when the declaration was made to him at Baghdad Abbas." In *bahaistories.com archive*, n.d..