To cite plotly in publications use:

Sievert C (2020). Interactive Web-Based Data Visualization with R, plotly, and shiny. Chapman and Hall/CRC. ISBN 9781138331457, https://plotly-r.com.

Corresponding BibTeX entry:

  @Book{,
    author = {Carson Sievert},
    title = {Interactive Web-Based Data Visualization with R, plotly,
      and shiny},
    publisher = {Chapman and Hall/CRC},
    year = {2020},
    isbn = {9781138331457},
    url = {https://plotly-r.com},
  }