Enter the base URL to the maven_metadata.xml for a given repository, groupId, artifact.
It is advised to use virtual repositories which serve all the desired artifacts (snapshots+releases).
Plugin downloads the following url construct:
[base_url]/[repository]/[groupId hierarchy expanded]/[artifactId]/maven-metadata.xml
i.e. base_url: https://maven.mycompany.com/content/repository
repository: myrepository
groupId: my.group.id
artifactId: my-artifactId
https://maven.mycompany.com/content/repository/myrepository/my/group/id/my-artifactId/maven-metadata.xml