Submit W-8IMY tax form

This POST endpoint is used to submit a W-8IMY tax form for a specific user identified by their user_token. The W-8IMY form is used by foreign intermediaries, foreign flow-through entities, or certain U.S. branches to certify their status for withholding purposes. This form is typically used by qualified intermediaries (QI), withholding foreign partnerships (WP), withholding foreign trusts (WT), and non-qualified intermediaries. Basic information (name, address, phone) is retrieved from the user's existing profile.
To use this endpoint, you need to provide the user_token as a parameter in the URL Path and the W-8IMY form data in the request body.