Ask HN:Serving Global customers being a local comapny

Imagine a non-US company serving US customers. Are there any legal issues aroubnd this? Should such company need to pay tax in US also?

If one starts a company outside US that is serving US customers, is it needed to pay tax in US as well as that country from where it is started?

I understand there is a need for lawyer advice here. But I just wanted to check if fellow HNites here have a firsthand experience.

Thanks.