With Sirena, you can log in with your Google or Facebook account. To do this, the user must have the e-mail used on his Facebook or Google account registered in Sirena.
You will be able to see and edit the e-mails of each user at https://web.sirena.app/manager/profile/groups
In order for the user to be able to log in this way, he must select "Login with Google" or "Login with Facebook".
* The first time you must grant access permissions from Google or Facebook.
In case that you wish to block access to the Sirena account, simply delete the email from your G suite.