I'm just following the tutorial here:

https://docs.adobe.com/content/help/en/experience-manager-learn/getting-started-wknd-tutorial-develo... 

and I launched the command :

 mvn -PautoInstallSinglePackage clean install

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for aem-guides-wknd 0.0.1-SNAPSHOT:
[INFO]
[INFO] aem-guides-wknd .................................... SUCCESS [  0.253 s]
[INFO] WKND Sites Project - Core .......................... SUCCESS [  4.976 s]
[INFO] WKND Sites Project - UI Frontend ................... SUCCESS [  8.875 s]
[INFO] WKND Sites Project - Repository Structure Package .. SUCCESS [  0.457 s]
[INFO] WKND Sites Project - UI apps ....................... SUCCESS [  2.534 s]
[INFO] WKND Sites Project - UI content .................... SUCCESS [  1.331 s]
[INFO] WKND Sites Project - All ........................... FAILURE [  0.318 s]
[INFO] WKND Sites Project - Integration Tests Bundles ..... SKIPPED
[INFO] WKND Sites Project - Integration Tests Launcher .... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  19.663 s
[INFO] Finished at: 2020-09-01T14:12:39+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.day.jcr.vault:content-package-maven-plugin:1.0.2:install (install-package) on project aem-guides-wknd.all: Connection refused -> [Help 1]

 I received the error:

Failed to execute goal com.day.jcr.vault:content-package-maven-plugin:1.0.2:install (install-package) on project aem-guides-wknd.all: Connection refused -> [Help 1]

How it's possible to follow a tutorial and receive an error?