To cite corrplot in publications use:

Wei T, Simko V (2021). R package 'corrplot': Visualization of a Correlation Matrix. (Version 0.90), https://github.com/taiyun/corrplot.

Corresponding BibTeX entry:

  @Manual{corrplot2021,
    title = {R package 'corrplot': Visualization of a Correlation
      Matrix},
    author = {Taiyun Wei and Viliam Simko},
    year = {2021},
    note = {(Version 0.90)},
    url = {https://github.com/taiyun/corrplot},
  }