You can't. It's been an often requested feature, but the slugs are hard coded throughout the NodeBB codebase.
Got it , Thanks
Should we use the meta name keywords?
Because I read this article and Google do not support it: https://support.google.com/webmasters/answer/79812?hl=en
And this article also stated that the use of it generate more negatives than positives:
Absolutely, meta data has many important uses. SEO is not one of them.
SEO is a bit of a mixed bag. I'd take any article with a grain of salt.
Meta keywords aren't really relevant anymore. It's a "nice to have". If you have it it's great, because Google isn't the only search engine in the world. But it absolutely does not impact negatively on SEO, unless you're padding it with unnecessary unrelated content, which is what Google wants to stamp out.