Can you grab the full URL from the network console in your browser that you're being redirected to? It should look like this: https://login.mypurecloud.com/oauth/authorize?client_id=96a7d55b-1ed5-4719-9094-08a2a69ca07c&response_type=token&redirect_uri=https://developer.genesys.cloud/&state=location%253D%25252F%2526region%253Dmypurecloud.com