RingCentral Widget don't let me register emergency calling address

Hello, I'm trying to use the widget of RingCentral that is hosted in: https://github.com/ringcentral-tutorials/ringcentral-widgets-demo

I downloaded the widget and just change the credentials (.env file) with my sandbox credentials and run it on localhost, when I login in the widget and RingCentral ask me to register a emergency calling address, it makes an error and don't let me allow to continue, the error says:

Internal error. Try again later or contact the support. [3057217003584252958]

I look at the console and marks me an error on a endpoint

I even try to configurate the address on: https://app.devtest.ringcentral.com/settings/company_administration and I have the same error