The Wikidata-Query-Service GUI repository does not contain a LICENSE file (or LICENSE.md) nor is a licence field included in package.json. package.json should also refer to the official code repository. I came from https://github.com/wikimedia/wikidata-query-gui but this is just a mirror. I bet I will have found the right repository in a few minutes but I would prefer not to have wasted this time of searching. The missing fields are also reported by npm:
$ npm install ... npm WARN wikidata-query-gui@0.1.3 No repository field. npm WARN wikidata-query-gui@0.1.3 No license field.