Medium will send you your Form 1042-S, which is the IRS Form that you should keep.

Medium won't file your IRS tax returns, that is something you need to do on your own. Start with getting an individual tax identification number (ITIN). Once you have that, and your Form 1042-S, you will have all the information you need to file your Form 1040-NR, which is the tax return.

Having all this paperwork can be useful when dealing with LHDN! I've been audited by LHDN before and they questioned every income source I had, as long as they were at least RM100 a month. It was quite challenging since I was a freelancer and I had a few small jobs from "one-off" clients.

If you don't have sufficient proof that your income is foreign-sourced income, i.e., your IRS tax returns, you risk having that amount added to your taxable income and taxed at whatever you tax rate is.

Hope that helps!