To cite package ‘opencage’ in publications use:

  Possenriede D, Sadler J, Salmon M (2024). _opencage: Geocode with the
  OpenCage API_. R package version 0.2.2.9000, ,
  <https://github.com/ropensci/opencage>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {opencage: Geocode with the OpenCage API},
    author = {Daniel Possenriede and Jesse Sadler and Maëlle Salmon},
    year = {2024},
    note = {R package version 0.2.2.9000, 
},
    url = {https://github.com/ropensci/opencage},
  }