Individual tax for non-US citizen and non-residents

Hi there

I am from Yemen and I work individually with Amazon in the United States .. I send designs that are printed on T-shirts by Amazon and I get a percentage for the designs only and Amazon owns the product and presses and so on.
My country does not have a tax treaty with the United States, but my income is directly related to Amazon business in US
What is the form that I have to fill in to be in the correct condition

Note: a year ago, I filled out the form W-8ECI to help reduce taxes because I am not a US citizen, I do not reside in the United States, and I do not fully own the products.
I got EIN, but I didn't give it to Amazon when filling in tax information because I'm not sure what I did.
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For my case, what should I do to get the best tax rate (legally).?

Thanks

Carl
Level 15

Business & farm

As a non-resident of the U.S. you can't use any version or flavor of TurboTax to file a U.S. tax return. You are required to file IRS Form 1040NR Non-Resident return. TurboTax does not have or support that form. You will need to use the service at www.sprintax.com to complete and file the 1040NR. Any questions you may have should be asked in their support forums.