Woooo hold on there.
ALL THE BELOW IS JUST MY LAYMAN’S EXPERIENCE
Tucker, you are UK based and apparently there is a treaty with the US to avoid the US’s “withholding tax” (not sure it is 30% for UK, might be 20%). You need to get an ITIN from the IRS, which you can do by filling in a form, and sending that with a notarized copy of your passport to the IRS. The easiest way to do this is at the IRS office in the US embassy in London – they will help you a lot and also notarize your passport for free. Not many people know this. I got my ITIN exactly this way.
I think you can also set up a corp and get an EIN. Up to you. Either way, you absolutely do not have to pay that tax, assuming it’s withholding tax. That’s what I was told.