How to add meta keywords in my website for SEO – Marketing

No, you don’t. None of the major search engines uses the meta keywords tag any more, so it’s just a waste of time to add it.

I’m not sure what you mean here by using “description method”. The meta description tag is important, but you need to right a good description, not use it for keyword stuffing. See Google’s “Search Engine Optimization Starter Guide” for further guidance on this and other aspects of SEO.