yamamoto

Hello I am trying to use the yamamoto function, as given in an example: on
this site:
R: Yamamoto (r-project.org)
<https://search.r-project.org/CRAN/refmans/BreakPoints/html/yamamoto.html>

but it doesn't seem to give the package when the function comes and it
doesn't work in base.  I can't actually find which package (I assume that
it is in a package) it is within.  I've tried "mediation2 and that doesn't
work.  Can anyone help? Thanks Nick WQray