To cite package ‘presize’ in publications use:

  Haynes et al., (2021). presize: An R-package for precision-based
  sample size calculation in clinical research. Journal of Open Source
  Software, 6(60), 3118, https://doi.org/10.21105/joss.03118

A BibTeX entry for LaTeX users is

  @Article{,
    title = {`presize`: An R-package for precision-based sample size calculation in clinical research},
    author = {Alan G. Haynes and Armando Lenz and Odile Stalder and Andreas Limacher},
    year = {2021},
    journal = {Journal of Open Source Software},
    volume = {6},
    number = {60},
    pages = {3118},
    doi = {10.21105/joss.03118},
  }