Almost all projects prohibit investing in US citizens. This is to protect projects from claims by the SEC.
If Garnex is registered in the USA, then they may have passed the SEC audit and are entitled to sell tokens to US citizens
I think this information will appear before the start of the token sale. Now the project has conducted only private sales
There is currently no white paper and the team is in no hurry to inform the community about the exchange where IEO will be held