Set/change your product name, I had this issue until I created a product name as same as project name. The product name can be set in the Consent screen section of the Google Developers Console for your project. Look under APIs & auth in the left navigation and select Consent screen. You need also to … Read more
The following parameter is supported in OAuth2 authorization URLs: prompt Currently it can have values none, select_account, and consent. none: Will cause Google to not show any UI, and therefore fail if user needs to login, or select an account in case of multi-login, or consent if first approval. It can be run in an … Read more
Update, 25 Oct 2018: As of 13 September 2018, there is now a much simpler way to access the user’s account if your project uses Google Sign-In. Google Sign-In for Assistant will give you an ID Token with information about the user, including their Google ID, with their permission. This permission can be granted just … Read more