With this little Extension Manager you can download Extension from CivitAI for Forge Neo.
If you use the Civitai Helper, it will use the API that is stored already in the settings. If not, you need to generate it and put it in the "Civitai API key (optional)" field and can hit the button "Save API key".
https://github.com/zixaphir/Stable-Diffusion-Webui-Civitai-Helper/wiki/Civitai-API-Key

Just copy the civitai adress of the extension you want to download and hit the "Install" button.

You can check for updates of your existing ones (right now it only recognizes previous downloaded ones from me, so if you have already installed extension from here from someone else, it will only work, after you installed it via this extension.