Hello! This might be a long-shot but would love someone's input if they knew the answer or knew someone who might know the answer!

I am opening a coffee shop and I would like a specific drink concentrate from America. I have friends coming to visit who are willing to pack it into their extra suitcase and save me $300 on shipping. However, they (or I) need to declare the goods in order to pay the import tax so that I can use it as a legitimate item and expense for my cafe. Does anyone know how to declare goods from America? And if so, does it need to be done by me or by the person who brings the items in their suitcase at the airport? If not at the airport, then where else could I declare them?

Thank you in advance for anyone who is able to help!

Greetings, This is not Visa related, Covid or the like. My fiance' in Sriracha is trying to mail me by Fed Ex a package of 5 bottles of the Mae Mali oil to the USA. The currier is telling her it is a controlled substance and requires a FDA request (in her words). She wrote it down as a gift as "essential oils" on the commercial invoice but the guy at Fed Ex tells her she needs the manufacturer's certificate and FDA request? How can we get it by them?