如何从R调用Amazon销售合作伙伴API

我正在try 使用HTTR包从Amazon SP API检索数据. 到目前为止，我所做的是:

(0)必备条件

library(httr)
library(httr2)
library(jsonlite)
library(lubridate)

(1)数据定义为:

data = list(
  grant_type = "refresh_token",
  refresh_token = "Atzr|...",
  client_id = "amzn1...",
  client_secret = "amzn1....")

获取(2)作为POST请求响应的"access_token"值:

token_response = httr::POST(
  url = "https://api.amazon.com/auth/o2/token",
  body = data) 

access_token = fromJSON(token_response)[["access_token"]]

我还(3)定义了请求参数:

markentplace_endpoint = "https://sellingpartnerapi-eu.amazon.com"
marketplace_id = "A1PA6795UKMFR9"

request_params = list(
  "MarketplaceId" = marketplace_id, 
  "CreatedAfter" = as_date(Sys.Date()-30))

和(4)和URL字符串:

url = paste0(markentplace_endpoint, "/orders/v0/orders")
url$query = request_params
url = paste0(paste0(markentplace_endpoint, "/orders/v0/orders"), url_build(url))

最后(5)发出GET请求

httr::GET(
  url = paste0(paste0(markentplace_endpoint, "/orders/v0/orders"), url_build(url)), 
  add_headers(`x-amz-access-token` = access_token))

最后，我已经陷入了步骤2，因为我从POST请求中得到了以下响应:

Response [https://api.amazon.com/auth/o2/token]
  Date: 2024-01-07 12:13
  Status: 400
  Content-Type: application/json;charset=UTF-8
  Size: 392 B

我基本上是在遵循这https://www.youtube.com/watch?v=gp5kTI8I3pU个教程，并试图适应R/R Studio.

有谁有更丰富的经验，愿意分享吗？