R ggpubr::ggtexttable spanner column

I need to add a spanner column using ggpubr::ggtexttable. I currently use a delimiter to separate the spanner name from the column name. I can accomplish what I need using gt; however, I need to use ggpubr to be able to match tables previously created.

Example with gt:

gt_tab<-
  iris %>%
  dplyr::select(-Species) %>%
  dplyr::slice(1:4) %>%
  gt() %>%
  tab_spanner_delim(delim = ".")

Thanks!