Facebook Access Token: MACHINE_ID - php

Question

I did a little PHP script that uses this principle: https://developers.facebook.com/docs/facebook-login/access-tokens/expiration-and-extension#long-via-code
Unfortunately when I send the CODE to the user and try to HTTPrequest (javascript), the page that should give me the MACHINE_ID responds with a random, changing string.
I guess HTTPrequest is called basically from the server, not the client. When I use direct URL connection I get the same string every time, but I cannot use the data, because it is just a web page, not a response.
Shouldn't the MACHINE_ID always be the same (for a certain device/browser session)?

Answer 1

{
"session_key": "5.xLL8XelWvN17yQ.1530200602.46-100004938759387",
"uid": 100004938759387,
"secret": "62818f28dadf1e5fdea17c70cc42b4e5",
"access_token": "EAAAAUaZA8jlABAF8vs7Xp3bYhFrUjGZC7IJVIkBtsxGEbwjIhy7PtysyYCZB4ZBZAlXNvxSbsYZA9giZC8ZBhWZCpaTuYxGZBhGSo0sb1r5R8XPjmxbSHZCjuQgxjcgPlbVwsAVdboRHEyyc9cN6FfPFz3Jv9cB8xguVk4gyRCD6JQ5fhHBXxdykQwl",
"machine_id": "GgI1W1EjtchM9UoB1IiILZke",
"session_cookies": [{
"name": "c_user",
"value": "100004938759387",
"expires": "Fri, 28 Jun 2019 15:43:22 GMT",
"expires_timestamp": 1561736602,
"domain": ".facebook.com",
"path": "\/",
"secure": true
}, {
"name": "xs",
"value": "46:xLL8XelWvN17yQ:2:1530200602:15323:8134",
"expires": "Fri, 28 Jun 2019 15:43:22 GMT",
"expires_timestamp": 1561736602,
"domain": ".facebook.com",
"path": "\/",
"secure": true,
"httponly": true
}, {
"name": "fr",
"value": "0LpS1kk8BIpMZ6ZnX.AWUXzwpmVcljO_CD31ozKSBgHno.BYGKXA.3G.AAA.0.0.BbNQIa.AWUgcG86",
"expires": "Fri, 28 Jun 2019 15:43:22 GMT",
"expires_timestamp": 1561736602,
"domain": ".facebook.com",
"path": "\/",
"secure": true,
"httponly": true
}, {
"name": "datr",
"value": "GgI1W1EjtchM9UoB1IiILZke",
"expires": "Sat, 27 Jun 2020 15:43:22 GMT",
"expires_timestamp": 1593272602,
"domain": ".facebook.com",
"path": "\/",
"secure": true,
"httponly": true
}],
"confirmed": true,
"identifier": "Christian.palele",
"user_storage_key": "7086edcf13fb66e64be979ea719e8cd24d658ed3bce735e4f871dc69eda26409"
}