Authenticatin issue within Salesforce

[ben2pop]

Hi friends, 

In my company we are using Salesforce and we would like to embed Dashboard withing Salesforce. 

I tried to use the following embed function: 

<apex:iframe src="https://selina.looker.com/embed/dashboards/459?allow_login_screen=true"  width="100%" id="theIframe"/>

if the user is authenticated the it will work perfectly ! 

if the user is not authenticated then it will redirect to the login page. In my company we use Google authentication and for some reason  when we try to login in Looker via google authentication through Salesforce then we get “accounts.google.com refused to connect.”

I have no idea how to solve it .. could you please help me 

Thx you very much