To cite package ‘flexMatch’ in publications use:

  Last F (2026). _flexMatch: What the Package Does (One Line, Title
  Case)_. R package version 0.0.0.9000,
  <https://github.com/avkazakovgit/flexmatch>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {flexMatch: What the Package Does (One Line, Title Case)},
    author = {First Last},
    year = {2026},
    note = {R package version 0.0.0.9000},
    url = {https://github.com/avkazakovgit/flexmatch},
  }