How to use meta keywords for seo?

Honestly, meta keywords aren't something you should spend much time on for SEO anymore, since Google officially confirmed back in 2009 that it completely ignores the meta keywords tag when determining rankings, and other major search engines followed a similar path shortly after. That said, if you're asking how to technically implement them anyway, perhaps for internal organization or because a specific platform still uses them for something like internal site search, you would add them within your page's head section using a meta tag formatted as content followed by a comma-separated list of relevant terms describing the page's topic. Some content management systems and e-commerce platforms still have a meta keywords field built into their SEO settings, largely as a legacy feature, and filling it in generally causes no harm even though it provides no ranking benefit whatsoever. Instead of investing time in meta keywords, your energy is far better spent on things that actually influence rankings, like writing a compelling meta title and description that improve click-through rates, naturally incorporating relevant keywords into your actual page content and headers, and building quality backlinks. Meta keywords are essentially a relic from early search engine history that no longer serves a functional SEO purpose today.