title: LTI compliant example for consumer and provider
body: <p>i'm looking for any code sample to integrate external tool to LMS using LTI in NodeJS but it seems quite hard to find working example.
  i have gone trough the sample provide by <a href="https://www.imsglobal.org/learning-tools-interoperability-sample-code" rel="nofollow noreferrer">IMS Global</a> but it's hard to understand. anyone having idea how to authorized app using LTI please share your code.</p>