If you are using TurboTax Online, at the top of the Contact Info page, there is a question that asks "Is your mailing address outside Canada?". Answer YES to that question to be allowed to put a foreign address in. The boxes will still ask for Canadian things like Postal Code, etc.. but you will be able to put whatever you need there without getting an error message that the format is not right.
If you are on the payment page, then unfortunately it will not take a foreign address because we only accept Canadian or US credit cards. But, if you don’t have a Canadian or US credit card, you can try purchasing a prepayment code from one of our retail partners. https://turbotax.intuit.ca/tax-software/where-to-buy.jsp
If you have an iOS or Android device, you can download our mobile app and use that to pay for your return with ApplePay or GooglePay. You can find our mobile apps here: https://turbotax.intuit.ca/personal-tax-software/mobile-app.jsp
You would use the same user name and login as you do for TurboTax Online.