Hi David,
To work in the US as an OT after receiving education in another country you must go through the OTED process.
Here is the link:
https://www.nbcot.org/Students/get-certified
"If you did not earn your entry-level master’s/doctoral degree in occupational therapy from a U.S.-accredited college/university, you must apply for the Occupational Therapist Eligibility Determination (OTED®) process. The OTED process will determine if your completed education, including fieldwork, meets the eligibility requirements to apply for the OTR certification exam. Education and fieldwork must be deemed comparable to current U.S. entry-level educational standards."
Good Luck!
Matt