Пример работы с подсказками DaData на R. Использует пакет httr (https://github.com/r-lib/httr)

suggest.r

library(httr)

url <- "https://suggestions.dadata.ru/suggestions/api/4_1/rs/suggest/party"

headers <- c(
  "Content-Type" = "application/json",
  Accept = "application/json", 
  Authorization = "Token YOUR_API_KEY")

body <- list(
  query = "7719402047")

r <- POST(url = url, 
        config = c(add_headers(headers), accept_json()),  
        body = body,
        encode = "json")

content(r)