To cite package ‘optparse’ in publications use:

  Davis T (2024). _optparse: Command Line Option Parser_. R package
  version 1.7.5, <https://github.com/trevorld/r-optparse>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {optparse: Command Line Option Parser},
    author = {Trevor L. Davis},
    year = {2024},
    note = {R package version 1.7.5},
    url = {https://github.com/trevorld/r-optparse},
  }