To cite package ‘leafpop’ in publications use:

  Appelhans T, Detsch F (2021). _leafpop: Include Tables, Images and
  Graphs in Leaflet Pop-Ups_. R package version 0.1.0,
  <https://github.com/r-spatial/leafpop>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {leafpop: Include Tables, Images and Graphs in Leaflet Pop-Ups},
    author = {Tim Appelhans and Florian Detsch},
    year = {2021},
    note = {R package version 0.1.0},
    url = {https://github.com/r-spatial/leafpop},
  }