this code returns me this: {"error": "unsupported_grant_type", "error_description": "Grant type None is not supported"}. What am i doing wrong?

app.get('*', (req,res) => {
res.sendFile(__dirname + "/test.html")
console.log(req.query.code)
const Body = {
    client_id: "870076989682360330",
    client_secret: "my secret",
    code: req.query.code,
    redirect_uri: "http://localhost:3000",
    grant_type: "authorization_code",
    scope :"scope"
}
if(req.query.code) {

    reqst.post({
        uri: "https://discord.com/api/oauth2/token",
        headers: {'Content-Type': 'application/x-www-form-urlencoded'},
        body: JSON.stringify(Body)
    }, (x,y,z) => {
        console.log(z)
    })

}

})