Thanks @mikael.gundhus , I was able to get the plugin to connect to Jira.
But I ran into some oddity. I am not sure if I am the only one running into this issue, but the button Create and Attach issues seems to be reversed? When I click on the Create Issue button the plugin takes me to the attach issue screen:
And when I click on the Attach issue button the plugin takes me to the create issue screen: MS-155 is an existing issue in Jira. If I type in a new issue, say, MS-200, which doesn’t exist in Jira, it tells me An error occurred: You are not permitted to view the requested resource.