When we want to configure the plugin to access to the Nexus repository Server version 3 (docker image sonatype/nexus3) we get the following error:

Nexus Repository Manager 2.x connection failed
org.apache.http.client.HttpResponseException: Not Found
at com.sonatype.nexus.api.dc.a(SourceFile:41)
at com.sonatype.nexus.api.dc.handleResponse(SourceFile:24)
at org.apache.http.impl.client.CloseableHttpClient.execute(SourceFile:222)
at org.apache.http.impl.client.CloseableHttpClient.execute(SourceFile:164)
at org.apache.http.impl.client.CloseableHttpClient.execute(SourceFile:139)
at com.sonatype.nexus.api.db.getRepositoryList(SourceFile:64)
Caused: com.sonatype.nexus.api.exception.RepositoryManagerException: Could not retrieve list of repositories
at com.sonatype.nexus.api.db.getRepositoryList(SourceFile:68)
at com.sonatype.nexus.api.repository.RepositoryManagerClient$getRepositoryList.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
at org.sonatype.nexus.ci.util.NxrmUtil.getApplicableRepositories(NxrmUtil.groovy:66)
at org.sonatype.nexus.ci.util.NxrmUtil$getApplicableRepositories.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:133)
at org.sonatype.nexus.ci.config.Nxrm2Configuration$DescriptorImpl.doVerifyCredentials(Nxrm2Configuration.groovy:96)

On the other hand, the Nexus platform plugin work well with the Nexus 2 Repository version (using the docker image sonatype/nexus see enclosed screenshot).