Cannot receive image of a graph on email alerts

I have setup Grafana with Prometheus data source. I was able to trigger email alerts to my mailbox but the image of the graph is not appearing on the email.

Note that I have already installed the “grafana-image-renderer” plugin and I am storing the graph images that are generated locally.

The plugin is running properly and I have also activate the option GF_RENDERER_PLUGIN_IGNORE_HTTPS_ERRORS.

Is there any additional configuration I need to perform apart from the configuration in the grafana.ini file?

Thanks