Cypress tests for social login using Deezer-API

I have a React app with Deezer API and I am using Cypress for testing. I don't know how to get access to the popup window in login test.

so the test steps should be as follows:

• visit localhost:3000
• click on login button
• new window will open and then I have to click on sing in with google button but I don't know how to access this window

My example test screenshot