他沒解釋太清楚，but he is not that wrong

https://www.irs.gov/individuals/international-taxpayers/foreign-tax-credit-choosing-to-take-credit-or-deduction
 

Basically you can choose to deduct or credit. If you choose credit and it is over the credit limit of the tax year, you can carry over to next year.

It's very complicated, l would hire a tax expert on this one.