How to apply the ICC function to multiple groups?

Question

I'm pretty new to programming and using R so please bear with me. I am trying to use the ICC function (psych package) to get some reliability values for my data. I have about 300 unique IDs and for each ID I have 9x2 ratings (so a total of 3 columns labeled "ID", "rater1", and "rater2"). My goal is to group the ratings by ID and then use the ICC function on the rater values.

I tried to use group_by() like so:

datafile <- read.csv("~filename", header = TRUE)

groupdf <- datafile %>%
   group_by(ID)

ICC(groupdf)

But I got this error message:

Error in if (!is.data.frame(groups) || tail(names(groups), 1L) != ".rows") { : missing value where TRUE/FALSE needed

I tried to use split(), and I ended up with a list of data frames, each data frame containing the listener ID and their corresponding ratings. I created a for loop to iterate over each data frame like this:

groupdf <- datafile %>%
    split(.$ID)


for(i in 1:length(groupdf))
{
  
   ratings <- groupdf[, c(2, 3)]

  ICC(ratings)
  print(ICC(ratings))
}

But I get this error:

Error in groupdf[, c(2, 3)] : incorrect number of dimensions

I get the same error if I try to use lapply(). It makes no difference whether I change the column numbers in the code.

At this point I think I'm at the limit of my syntax skills. Can anyone help me see what is missing here? Thank you for your help!