While you are waiting for the official release on Community Plugins, you can download from this repository. Click on release and choose the latest release.
download the file named google-bard-assistant.zip, open it up.
click on folder icon on community plugins at settings sidebar (Obsidian Desktop app). It will open folder where all of your obsidian vault plugins are saved.
Then drag the folder from zip you opened to the folder that is shown to you. Then you can click on the reload icon beside the folder icon.