Install on your Atlassian Instance by pasting https://markus-arndt.com/_haystack/jira-alljs-ts-demo/atlassian-connect.json on https://<your instance>.atlassian.net/plugins/servlet/upm (dev mode needs to be enabled in UPM > Settings).
Fix the deployment path (baseUrl) in atlassian-connect.json.
$ npm install
$ npm run build