The plugin should still work, but we discontinued the centralised OAuth management service, so you need to manage renewing OAuth every 30-90 days yourself, and you need to define an OAuth application for your Jenkins instance and the redirect URL of that app must be on the public internet IIRC (there may be hacks, but I could never figure them out)
Not sure if the plugin was selected for open sourcing or not, or the status of the plugin - the responsibility for that plugin was handed to another team some time ago, and I have also moved teams a couple of times since.