How to Enable Plugins in Opera Browser? Open Opera browser on your computer. Click on the opera icon at the top of the browser. Hover your mouse on the settings tab and select “Preferences.” Prefernces Dialouge box will appear. Click on the “Advanced” tab. Choose “content” in the left-hand panel. Select the check box ” Enable Plugins”. Click ok to Apply the changes. This is How You can Enable Plugins in Opera Browser.