To cite package ‘ip2whois’ in publications use:

  IP2WHOIS (2024). _ip2whois: Lookup 'WHOIS' Information for a
  Particular Domain_. R package version 1.0.0,
  <https://CRAN.R-project.org/package=ip2whois>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ip2whois: Lookup 'WHOIS' Information for a Particular Domain},
    author = {{IP2WHOIS}},
    year = {2024},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=ip2whois},
  }