I want to export the ebird relative abundance raster as a TIFF file, but I encountered this Error: external pointer is not valid and I don’t know why.

Here is my code:

library(fields)
library(rnaturalearth)
library(sf)
library(terra)
library(ebirdst)

set_ebirdst_access_key("q1kum0g8p0k")
# download data, Anas acuta
ebirdst_download_status(species = "Anas acuta")

# load relative abundance raster 
abd <- load_raster("Anas acuta", resolution = "27km",product = "abundance",
                   period = "full-year"
                   )

writeRaster(abd, filename = "ebrid_test.tif")

I just want to save the species full-year relative abundance raster from ebird.