The following discussion covers setting up SonarQube for a javascript project: https://community.sonarsource.com/t/sonarcloud-analysis-for-javascript-application/10591/3
I just went through the process for the first time. The key is getting the lcov.info file, which Elena mentioned can be produced by Karma. The following setting causes the coverage info to be published to your SonarQube project:
sonar.javascript.lcov.reportPaths=coverage/lcov.info
Note the path is relative to the project root.