30.12.2017 13:39
Launch the browser and click on More (⋮) → Settings (see pic. 1).
At the bottom, click on Advanced → Content settings (see pic. 2).
Scroll down the web page and select Popups (see pic. 3).
If you want to enable this option, then switch on Blocked (recommended) as shown in picture 4. The status will be changed from Blocked to Allowed.