Installing the WP subscriptions widget on a self-hosted blog

Hi! I’m running a self-hosted WP blog and would love to install the WP blog subscriptions widget. I don’t seem to get the option to install it though. Is it not available to self-hosted blogs?

Does anyone know a way around this?

Are there any other good email subscription widgets anyone can recommend instead?

Thanks!!!

https://www.thehambledon.com/blog