Mirt model problem

Hi, I´m trying to do mirt model

After installing mirt, lattice, and stats4 in mac I run the following syntaxes:
mod1 <- mirt(data, 1, itemtype = "Rash")
But I got this error: Error in if (length(unique(colnames(data))) != ncol(data)) stop("items must have unique names in data input", :
argument is of length zero

It looks like this is the part of the code throwing the error:

Before suggesting that you file an issue for the package, it would be helpful if you could give a reproducible example, so others can help troubleshoot here.

A self-contained reprex (short for reproducible example) will help us help you, since we can be sure we're all working with/looking at the same stuff.

install.packages("reprex")

If you've never heard of a reprex before, you might want to start by reading the tidyverse.org help page. The reprex dos and don'ts are also useful.

There's also a nice FAQ on how to do a minimal reprex for beginners, below:

What to do if you run into clipboard problems

If you run into problems with access to your clipboard, you can specify an outfile for the reprex, and then copy and paste the contents into the forum.

reprex::reprex(input = "fruits_stringdist.R", outfile = "fruits_stringdist.md")

For pointers specific to the community site, check out the reprex FAQ.