error test download

[fipoucat]

I am running the example but get error message and wonder what is causing it?

dataset <- "reanalysis-era5-single-levels"
request <- "{

•         'variable': 'mean_sea_level_pressure',
  

•         'grid': ['0.1', '0.1'], 'product_type': 'reanalysis',
  

•         'year': '2010', 'month': '08', 'day': '15', 'time': '12:00',
  

•         'area': '45.0/-15.0/70.0/25.0',
  

•         'format': 'netcdf'
  

•         }"
  

result <- cds_retrieve( dataset, request)
Error in POST(dataURL, body = req, encode = "json", authenticate(cdsUID, :
could not find function "POST"