Especially multi-module projects have to run mvn verify site site:stageand include a property <scmpublish.content>target/staging/ARTIFACTID</scmpublish.content>, take a look at the mojo documentation as well.
After running mvn verify site site:stage, execute mvn scm-publish:publish-scm.
Note that child projects have to do two things:
src/site/resources/.nojekyll(see publishing maven site on github having jacoco).mvn verify site site:stageand include a property<scmpublish.content>target/staging/ARTIFACTID</scmpublish.content>, take a look at the mojo documentation as well.mvn verify site site:stage, executemvn scm-publish:publish-scm.