UnityWebRequest.Post with MultipartFormDataSection returns Bad Request (400)

Hello,

I've created a node.js server to post data to database table, this is my node.js code snippet:

 router.post('/register', async function(req,res){
     try{
         const {id, name} = req.query;
         const sqlQuery = 'INSERT INTO TestTable (id, name) VALUES (?,?)';
         const result = await pool.query(sqlQuery, [id, name]);
         console.log(result);
         res.status(200).json(result);
     } catch(error){
         res.status(400).send(error.message)
     }
 })

Following a tutorial (https://www.youtube.com/watch?v=krTbf0O-BCo), I first tested the post method with Postman software, and I was able to write to the TestTable with the localhost succesfully:

Next step was to call the "post" method using REST API from Unity, and my goal was to pass the URL, similarly to the URL as it is in postman:

localhost:8000/user/register?id=2232&name=somename

This is the "Post" method code snippet from Unity:

 private const string POST_DB_URL = "http://localhost:8000/user/register";
 
         private IEnumerator PostCourseCreditInternal() {
             List<IMultipartFormSection> formData = new List<IMultipartFormSection>();
             formData.Add(new MultipartFormDataSection("id=5555&name=somename"));

             var postRequest = UnityWebRequest.Post(POST_DB_URL, formData);
             yield return postRequest.SendWebRequest();
 
             if (postRequest.isHttpError) {
                 Debug.Log("request resulted in error: " + postRequest.error);
             }
             if (postRequest.downloadHandler.isDone) {
                 Debug.Log(postRequest.downloadProgress);
             }
         }

This returns an error 400 - bad request, I wonder if it is the syntax or maybe some privacy limitations due to VPN usage in my work?

Should I use the UnityWebRequest.Post or should I use UnityWebRequest.Get to post?

Thanks for any help