fix - checking grant_type

main.go

@@ -389,10 +389,9 @@ func main() {
 		data.Set("client_id", clientId)
 		data.Set("client_secret", clientSecret)
 		data.Set("grant_type", grantType)
-		if code != "" {
+		if grantType == "authorization_code" {
 			data.Set("code", code)
-		}
-		if scope != "" {
+		} else {
 			data.Set("scope", scope)
 		}