Function headless_lms_server::controllers::main_frontend::course_instances::preview_post_completions

async fn preview_post_completions(
    course_instance_id: Path<Uuid>,
    pool: Data<PgPool>,
    user: AuthUser,
    payload: Json<TeacherManualCompletionRequest>
) -> ControllerResult<Json<ManualCompletionPreview>>