Is it good for SEO to have domain alias that describes company service? [duplicate]

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  • Will having multiple domains improve my seo? 7 answers

I have bought a domian that is like service.city.example Where service is eg. “haircut”.

Is it good to have this kind of domains as aliases to main domain company.example?

What would be best for SEO, serving the main domain content on this alias or redirect 301 from alias to main domain?