Question about sourcing SN in the US

[Kali_Yuga13]

I am having trouble finding out how to source SN in the US. I found one vendor for reagent grade 95% but during the check out they ask for a business identifier. I don't know how official that is or if I can just make something up. I've seen abbreviations for vendors used here but found nothing that stands out as corresponding. I don't plan on ctb anytime soon but I would like SN as a safety blanket. Did the crackdown make it nearly unattainable at this point? I've read that Poland has vendors but I'm not sure about shipping though. I would like to source in the US if possible though. Any ideas? I'd be willing to accept DMs.