Google drive api rest upload file with service account not works

After creating a service account from the google iam console, and having obtained the json with the private_key,client_email and so on... I have problems integrating them into my javascript code to upload a file to google drive with an authentication server to server. With the use of nodejs I didn't have any problem (I used JWTtoken), I would be grateful if you could help me to insert the authentication parameters correctly in the javascript post request code of the example.

       $.ajax({
        type: "POST",
        url: "https://www.googleapis.com/upload/drive/v3/files",
        data:{
            uploadType:"multipart",
            parents: ["xxxxxxxxxxxxxxxxxxxxxxxx"]
        },
        success: function (data) {
            console.log(data);
        },
        error: function (error) {
            console.log(error);
        },
        async: true,
        data: formData,
        cache: false,
        contentType: false,
        Authorization: ????????????????? <---
        processData: false,
        timeout: 60000
    });
};

When I try to do to update this file I see no result. Can someone help me?

from Google drive api rest upload file with service account not works