I have a Japanese phone number. It only allows me to enter a US number and won’t let me submit without a phone number. Ideas?

Yes, there's a work-around for this issue.

Select Intuit Account in the lower left of the TurboTax page and enter a U. S. phone number, then your password and save it. 

It doesn't need to be your phone number, or even a valid phone number because when you go to file the return, it gives you an option to get email updates ‌or text messages.  

Just make up a U. S. number if needed and don't check the box saying you want text messages and you should be able to get the taxes filed.