I'm getting a white box surrounding Google One Tap

Question

I'm getting a white box surrounding Google One Tap:

The code is this:

this.init = function () {
        google.accounts.id.initialize({
            client_id: "XXXXXXXXXXXXXXXXXXXX",
            auto_select: false,
            callback: cw.handleCredentialResponse,
            cancel_on_tap_outside: false,
        });

        google.accounts.id.prompt();
    }

I was expecting the same, but without the white box.