Customization of Squarespace website

I am trying to optimize my Bedford template for SEO. I use a banner on each page, and the text for the banner is used for the meta description for search, which I do not want. I tried to inject a meta description in "code injection header" but it is not "seen." Can you devise a solution so that I can place a different description on each page's banner and have a meta description for SEO that is independent.