Beginner: How to run a simple custom plugin outside of buildSrc

I am really new to Gradle so this might a silly question. I want to build a plugin and publish it, but I also want to test it locally.

I built the plugin by placing source code in buildSrc which worked great. However, my understanding is that to publish it I need to move it out of buildSrc. When I do this, I can’t see how to actually run the plugin locally to test it. Do I need to do use a local maven repository? Shouldn’t there be an easy way to do this like when it was in buildSrc?

For example, I cloned https://github.com/gradle-guides/greeting-plugin-example and if I hit “run” the “hello” task is not created but the build is successful.

I use a composite build. See an example here with two projects, one for the plugin, another to test it. I tend to keep the version in a version.txt file to share between the two builds