Regardless of your location, all monetizing creators on YouTube are required to provide tax info.
You're being asked to complete this form in order for Google to comply with its obligations under the United States Internal Revenue Code Sections 1441 (Chapter 3) and 3406.
This form is used to identify the correct rate of withholding taxes on earnings you generate from viewers in the U.S., if applicable. If your tax info isn’t provided by May 31, 2021, Google may be required to deduct up to 24% of your total earnings worldwide.
How to submit/update tax info
Sign in to your AdSense account.
Click Manage settings.
Scroll to Payments profile and click edit next to United States tax info.
Click Manage tax information.
On this page, you'll find a guide that will help you to select the appropriate form for your tax situation.
Your channel’s revenue will continue being paid out to the Network. If any withholding taxes apply, these will be withheld from the payment made to the Network for your channel’s revenue.