when i try to run blueocean-plaugin-master project using maven command is  mvn clean install  then facing following issue

[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]
[ERROR] The project io.jenkins.blueocean:blueocean-parent:1.8.0-beta-1-SNAPSHOT (/all/cpp_source/blueocean-plugin-master/pom.xml) has 1 error
[ERROR] Non-resolvable parent POM for io.jenkins.blueocean:blueocean-parent:1.8.0-beta-1-SNAPSHOT: Could not transfer artifact org.jenkins-ci.plugins:plugin:pom:3.15
from/to repo.jenkins-ci.org (http://repo.jenkins-ci.org/public/): repo.jenkins-ci.org: unknown error and 'parent.relativePath'
points at wrong local POM @ line 5, column 11: Unknown host repo.jenkins-ci.org: unknown error

Please find attached pom.xml file if i need to change plz let me know