While this code works, it sends "Bad Request".

import socket, ssl
token = 'NzMyMzQ1MTcwNjK2MTR5OEU3.XrzQug.BQzbrckR-THB9eRwZi3Dn08BWrM'
HOST = "discord.com"
PORT = 443
t = 'POST / HTTP/1.0\r\nAuthentication: Bot {token}\r\nHost: discord.com/api/guilds/{702627382091186318}/channels\r\n\r\n'
context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s_sock = context.wrap_socket(s, server_hostname=HOST)
s_sock.connect((HOST, 443))
s_sock.sendall(t.encode())f = s_sock.recv(7000).decode()
print(f)s_sock.close()

Note: this is not a real token.

t = 'POST / HTTP/1.0\r\nAuthentication: Bot {token}\r\nHost: discord.com/api/guilds/{702627382091186318}/channels\r\n\r\n'

This is not a valid HTTP request. You essentially send (line breaks added for clarity):

 POST / HTTP/1.0\r\nAuthentication: Bot {token}\r\nHost: discord.com/api/guilds/{702627382091186318}/channels\r\n\r\n

But a correct POST request would look like this instead:

 POST /api/guilds/{702627382091186318}/channels HTTP/1.0\r\nAuthentication: Bot {token}\r\nHost: discord.com\r\nContent-length: ...\r\n<body, where size matches Content-length header>

I.e. you have the wrong path, wrong Host header, missing body and missing Content-length header. If you really want to write your own HTTP stack instead of using existing libraries please study the standards instead of just guessing how it might look - that what standards are for.