writexl - mtcars car model names not writing in output file

Hi Experts
I’m new to R. I tried to download writexl and exported mtcars data frame into an mtcars.xlsx using write_xlsx.
The output didn’t include the car model names other attributes were exported starting with mpg.
In write.csv it exports the car model name, though.
While viewing in RStudio, the content of mtcars data frame the car model doesn’t have any header.
I searched the forum for any answer but couldn’t find one.
Did anybody else noticed? How to get that ?
Thanks in Advance
M N Gangolli

thanks for your question @seeker - For general R questions such as this, a good place to ask is StackOverflow with the [r] tag