5chの自動投稿スクリプトを作ろうとしてるんだがうまくいかない

def main():
url = "https://mi.5ch.net/test/bbs.cgi";
kakikomi(url)

def kakikomi(url):
user_agent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.80 Safari/537.36"
referer = 'https://mi.5ch.net/test/read.cgi/news4vip/1644255243/l50'
headers = {
'referer': referer,
'User-Agent': user_agent,
'accept-encoding': 'zip, deflate, br',
'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
'accept-charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.3',
'accept-encoding': 'none',
'accept-language': 'ja,en-US;q=0.9,en;q=0.8',
'connection': 'keep-alive'
}
payload = {
"FROM" : "",
"mail" : "",
"MESSAGE" : "testst".encode('cp932'),
"bbs" : "news4vip",
"key" : "1644255243",
"time" : math.floor(time.time()),
'submit':'書き込む'.encode('cp932'),
"oekaki_thread1": ""
}
cookies = {
"yuki" : "akari",
"READJS" : ""
}

res = requests.post(url, data=payload, headers=headers, cookies=cookies)
print(res.text)

main()