如何将木偶操作者的焦点转移到弹出窗口

I'm using Puppeteer to run a test within a website. Once a button has been clicked, a new popup browser window appears with a report. Within that new window is information I'd like to extract. How can I get puppeteer to shift it's focus to this newly created browser window?I'm using Puppeteer to run a test within a webs