Lua socket HTTP getting connection refused - sockets

Question

I'm trying to create a function that creates an issue to a Github repository using Lua socket.http, but I'm getting connection refused everytime. The documentation for socket is a bit unclear and I couldn't find more helpful information on why is the request getting refused every time. I tried the following:
local config = {
token = "oauth token from github"
}
local http, ltn12 = require("socket.http"), require("ltn12")
local payload = '{"title": "Test", "body": "Test body", "labels": ["bug"]}'
local response, status, headers, line = http.request("https://api.github.com/repos/<username>/<repository>/issues?access_token=" .. config.token, payload)
So I checked again how to do and there is a second form to do a request. I'm trying the following:
local response = {}
local _, status, headers, line = http.request{
url = "https://api.github.com/repos/<username>/<repository>/issues",
sink = ltn12.sink.table(response),
method = "POST",
headers = {
["Authorization"] = "token " .. config.token,
["Content-Length"] = payload:len()
},
source = ltn12.source.string(payload)
}
According to socket documentation, this should make POST request to the URL sending the payload as body. If I print(status) it prints connection refused.
I'm ignoring the first return value as it always is 1.
I tried manually issuing the request using curl:
curl -H "Authorization: token <oauth token from github>" https://api.github.com/repos/<username>/<repository>/issues -XPOST -d '{"title": "Test", "body": "{"title": "Test", "body": "Test body", "labels": ["bug"]}'
And it posted the issue properly. I still can't figure it out what is happening that the connection is getting refused.