To cite qualR in publications use:

  Gavidia-Calderón, M., Schuch, D., Andrade, Maria de Fatima (2022).
  qualR: An R package to download Sao Paulo and Rio de Janeiro air
  pollution data. URL: https://docs.ropensci.org/qualR/

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {qualR: An R package to download São Paulo and Rio de Janeiro air pollution data},
    doi = {10.5281/zenodo.5904262},
    author = {Mario Gavidia-Calderón and Daniel Schuch and Maria de Fatima Andrade},
    year = {2022},
    url = {https://docs.ropensci.org/qualR/},
  }