generate_alpha_change_test_pair(): Error in `dplyr::group_by()`: ! Must group by variables found in `.data`. ✖ Column `time` is not found.

[qqwxp]

This is my script:

generate_alpha_change_test_pair(
  data.obj = MicrobiomeData,
  alpha.obj = NULL,
  alpha.name = c("shannon", "simpson", "observed_species", "chao1", "ace", "pielou"),
  time.var = "TimePoint",
  subject.var = "Individual",
  group.var = "Treatment",
  adj.vars = NULL,
  change.base = 1,
  alpha.change.func = "absolute change"
)

My time.var is "TimePoint". I got a error show that "Column time is not found." I have check the script of generate_alpha_change_test_pair() function, and I see the variable time first appears on line 30; before that, it was not defined (time.var was not assigned to it).