I cant have internet connection with host. though I have the whole zip file of the plugin, from git. so I have to manually install the plugin. but sadly the git doc doesnt have manual install guide provided.
checked the doc, readme.md in the zip. did search around for a while.
Sounds like you have a zip format of the logstash plugin. you. can use below command to install logstash plugin.
/usr/share/bin/logstash-plugin install file:///path/to/logstash-offline-plugins-7.17.13.zip
Reference : https://www.elastic.co/guide/en/logstash/7.17/offline-plugins.html