How to install index-management plugin to minimal distro?

Sorry if this is a stupid question but how should I install this plugin to a minimal opensearch install?

Say I dl and unzip it, then I cd into it and run the plugin install, it says the plugin is unknown:

./opensearch-plugin --verbose install opensearch-index-management
-> Installing opensearch-index-management
-> Failed installing opensearch-index-management
-> Rolling back opensearch-index-management
-> Rolled back opensearch-index-management
A tool for managing installed opensearch plugins

Non-option arguments:
[String] -- command  

Option             Description        
------             -----------        
-E <KeyValuePair>  Configure a setting
-h, --help         Show help          
-s, --silent       Show minimal output
-v, --verbose      Show verbose output
ERROR: Unknown plugin opensearch-index-management

Did I get the plugin name wrong or something? In the full-fat tarball the IM plugin has that name.

Are there build artefacts somewhere that I can point the install command to by URL? I found the following:

(also the job scheduler plugin it depends upon) but I wasn’t sure if that’s the best place to dl from.