To cite package sit in publications use:

  Facundo Muñoz (2021). sit: Analyse Mark-Release-Recapture Data from
  Sterile Insect Technique Field Experiments. Joint FAO/IAEA Centre of
  Nuclear Techniques in Food and Agriculture.
  https://umr-astre.pages.mia.inra.fr/sit

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {{sit: Analyse Mark-Release-Recapture Data from Sterile Insect Technique Field Experiments},
    author = {Facundo Muñoz},
    organization = {Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture},
    year = {2021},
    url = {https://umr-astre.pages.mia.inra.fr/sit},
  }