To cite rb3 in publications use:

  Download and parse public files released by B3 and convert them into
  useful formats and data structures common to data analysis
  practitioners.

A BibTeX entry for LaTeX users is

  @Manual{rb3-package,
    title = {Download and Parse Public Data Released by B3 Exchange},
    author = {Wilson Freitas and Marcelo Perlin},
    year = {2023},
    note = {R package version 0.0.8},
    url = {https://github.com/ropensci/rb3},
  }