Use the LTI Advantage Submission Review Service to launch back to an assessed item from a platform gradebook

Steps

1. Confirm the platform's LTI Advantage implementation declares the Submission Review Service (https://purl.imsglobal.org/spec/lti-sr/v1p0) in its service claims; the claim surfaces in the LTI launch JWT under the submission review key.
2. When a score is posted via AGS (POST to the lineitem scores endpoint), include the submissionReview object in the Score payload with endDateTime and externallyGraded fields to signal a reviewable submission.
3. When the platform triggers a review launch, validate the incoming LTI 1.3 JWT signature using the platform's JWKS endpoint; confirm the message_type claim equals LtiSubmissionReviewRequest.
4. Extract the for_user claim (the student whose submission is being reviewed) and the line_item claim (the assignment context) from the JWT to load the correct submission artifact in your tool UI.
5. Render the submission view scoped to the for_user; optionally accept an updated score from the reviewer and POST it back to the AGS scores endpoint with the activityProgress and gradingProgress fields updated.
6. Return a well-formed LTI response that closes the review window gracefully; do not re-launch a new OIDC flow from within the review view.