Sooner or later Google app will suggest you to use your device to accept and decline the access to your Google Account. If you agree, you will receive log in requests on this device when you sign in to your account on a new piece of hardware.
You will see the “Unlock your Pixel” or “Unlock your Galaxy S10” prompt on a new device, then you are to take your trusted device in hands and tap Yes to confirm that it is really you trying to log in to your Google account (Gmail, YouTube, Google Photos, or whatever from Google ecosystem).
But in some cases you may want to exclude a particular phone or tablet from the list of trusted devices.
