If instead of issue related information you see the issue’s key and "Authorize to see the issue" message:
"Authorize to see the issue"
You have to authorize Smart issue to allow the plugin to access your Jira account. This is a very easy, one-time operation that you have to perform.
Learn more about it at https://dirtyagile.atlassian.net/wiki/spaces/SJI/pages/452657263