Admin endpoint for tyk on premise installation

Trying to implement the oauth flow in tyk.

curl -X POST \ \
  -H 'Authorization: 70c3d834d46a4d6076e1585b0ef2e93e' \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  -d 'response_type=code&client_id=ed59158fa2344e94b3e6278e8ab85142&'

to get the authorization code this request needs to be sent. For a cloud setup what will be the url for on premise tyk installation. Given my gateway runs on localhost:8080 and dashboard at localhost:3000.