I need to Integrate Hubspot into my .asp application but don't know how to POST

Hi

I am a total beginner in Hubspot and JSON

My application has a landing page (.asp) where I have gathered all my client details and I now have to update Hubspot.

Looking at their manuals I guess I need to put all my variables in a <script> </script> like below:
<script>
{
  "properties": [
    {
      "property": "email",
      "value": "test@hubspot.com"
    },
    {
      "property": "firstname",
      "value": "HubSpot"
    }
  ]
}
</script>

firstly is this correct?

then I need to do a post with a command like:
Example POST URL:
https://api.hubapi.com/contacts/v1/contact/createOrUpdate/email/testingapis@hubspot.com/?hapikey=demo

secondly, how do I do this post in my .asp file to send the data?

Please can you help as I don't know where to start?  as Hubspot don't seem to want to get involved in any integrations.

Thanks Terry