To cite the FORTLS package in publications use both:

  Molina-Valero, J. A., Martínez-Calvo, A., Ginzo Villamayor, M. J.,
  Novo Pérez, M. A., Álvarez-González, J. G., Montes, F.,
  Pérez-Cruzado, C. (2022). Operationalizing the use of TLS in forest
  inventories: The R package FORTLS. Environmental Modelling &
  Software, 105337. <doi.org/10.1016/j.envsoft.2022.105337>.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Juan Alberto Molina-Valero and Adela Martínez-Calvo and Maria José Ginzo-Villamayor and Manuel Antonio Novo Pérez and Juan Gabriel Álvarez-González and Fernando Montes and César Pérez-Cruzado},
    title = {Operationalizing the use of TLS in forest inventories: The R package FORTLS},
    journal = {Environmental Modelling & Software},
    pages = {105337},
    year = {2022},
    doi = {10.1016/j.envsoft.2022.105337},
    url = {https://doi.org/10.1016/j.envsoft.2022.105337},
  }

  Juan Alberto Molina-Valero, Adela Martínez-Calvo, Juan Gabriel
  Álvarez-González, Fernando Montes and César Pérez-Cruzado (2026).
  Automatic Processing of Terrestrial-Based Technologies Point Cloud
  Data for Forestry Purposes. R package version 2.0.1.
  https://CRAN.R-project.org/package=FORTLS

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Automatic Processing of Terrestrial-Based Technologies Point
Cloud Data for Forestry Purposes},
    author = {Juan Alberto Molina-Valero and Adela Martínez-Calvo and Juan Gabriel Álvarez-González and Fernando Montes and César Pérez-Cruzado},
    year = {2026},
    note = {R package version 2.0.1},
    url = {https://CRAN.R-project.org/package=FORTLS},
  }