how to add a meta description tag

Hi - my site I'm building is https://akpwebservices.co.uk/ - I use generatepress premium.

I'm using SmartCrawl (https://wordpress.org/plugins/smartcrawl-seo/) and on running a check, I get the following:

Recommendation

The meta description is missing from this page. A good meta description will help boost your PageRank and attract more visitors.
Make sure your page has a meta description tag.

What's the best way to put this in my site? I also have Jetpack installed - maybe there's something in there I can use?

Thanks
A :-)