get_vernacularName <- function(scientific_name) {
  key <- name_backbone(scientific_name)$usageKey
  if (!is.null(key)) {
    name_usage(key, return = "data", data = "vernacularNames") %>%
      distinct(language, tolower(vernacularName)) %>%
      mutate(scientificName = scientific_name) %>%
      rename("vernacularName" = "tolower(vernacularName)") %>%
      select(scientificName, language, vernacularName)
  } else{
    warning(paste0("Scientific name ",
                   scientific_name,
                   " doesn't exists in GBIF Backbone.")
    )
    NULL
  }
}

names <- c("Vulpes vulpes", "Brachiopoda", "fake name")
map_dfr(names, get_vernacularName)