Tab: Marketing > Website (the Business: Website tab). Three text settings, global only:

• Website SEO Name – used as the site name in the browser tab title (page title + this name), in social-sharing metadata and in the web-app manifest.
• Website Description – the description shown in search/social previews and on the maintenance page.
• Website Keywords – the keywords meta tag for every page (individual pages can override it).

These are separate from Company Name, which is your legal/brand name used in emails and the footer.