Google Assistant test app unavailable in my country

Question

I've been following this tutorial on using Dialogflow and Firebase so I can control a simple website, but when trying to Talk to <app name> I receive the response

<app name> isn't available on devices set up for your language or country. Sorry about that.

I am located in New Zealand, but I did go into the settings for my google assistant and change the search language to English (US) and my search region to United States, although I get the same results, is there any way I can fix this or is there any way around it? Thanks

Answer 1

Following Nick Felker's comment, changing my phone's locale to English (US) enabled me to test the app. Thanks Nick!