Error when uploading a thumbnail via youtube API with R

I want to use R to update thumbnails of my youtube videos. I'm following the google documentation, but I get the following error:

"The request does not include the image content."

The curent status of my code is the following:

library(httr)
library(tuber)

video.id <- [ID]
thumbnail.path <- [path]
youtube.client.id <- [ID]
youtube.client.secret <- [secret]

yt_oauth(
    app_id = youtube.client.id,
    app_secret = youtube.client.secret,
    scope = 'partner'
)

req <- POST(
    "https://www.googleapis.com",
    path = paste0(
        "youtube/v3/thumbnails/set",
        "?videoId=", video.id
    ),
    body = httr::upload_file(thumbnail.path),
    config(token = getOption("google_token"))
)

I have similar queries for other API call (using PUT or GET), and they work. I think the issue is around the upload_file, but cannot find what should be the solution.

How can I fix that? Thanks in advance

Solution

If anyone has the same issue, I managed to fix it. I've tried a lot of things, but I think what really fixed it was to change the url from "youtube/v3/thumbnails/set" to "upload/youtube/v3/thumbnails/set".

Here is my final code:

oauth <- paste0('"Authorization: Bearer ', access.token, '"')
full.url <- paste0(
    'https://www.googleapis.com/upload/youtube/v3/thumbnails/set',
    '?videoId=', video.id,
    '&key=', youtube.api.key,
    '&uploadType=media'
)


final.args <- c(
    '--request', 'POST',
    '-v', paste0('"', full.url, '"'),
    '--data-binary', paste0('@', cover.path, ''),
    '-H', oauth,
    '-H', '"Content-Type: image/png"'
)


system2(
    command = 'curl',
    args = final.args,
    stdout = file.res, stderr = file.err
)