To cite didimputation in publications use:

Butts K (2021). didimputation: Difference-in-Differences estimator from Borusyak, Jaravel, and Spiess (2021). https://github.com/kylebutts/didimputation.

Corresponding BibTeX entry:

  @Manual{,
    title = {didimputation: Difference-in-Differences estimator from
      Borusyak, Jaravel, and Spiess (2021)},
    author = {Kyle Butts},
    year = {2021},
    url = {https://github.com/kylebutts/didimputation},
  }