Cant get sandbox token for Bing Ads anymore - says redirect_uri is not valid

Cant get sandbox token for Bing Ads anymore. This used to work.

I see the instructions have changed and now you need an outlook.com email vs outlook-int.com. I tried the url (with PROD_CLIENT_ID replaced with my client id):

https://login.microsoftonline.com/common/oauth2/v2.0/authorize?client_id=PROD_CLIENT_ID&scope=openid%20profile%20https://si.ads.microsoft.com/msads.manage%20offline_access&response_type=code&redirect_uri=https%3A//login.microsoftonline.com/common/oauth2/nativeclient&state=ClientStateGoesHere&prompt=login

But it just takes me to a page with the following error: invalid_request: The provided value for the input parameter 'redirect_uri' is not valid. The expected value is a URI which matches a redirect URI registered for this client application.

It use to provide back the code you would then use to fetch the