Blur effect

So I want this frame to blur and so I clicked the blur button and nothing happened. It disabled the select, brush, eraser, and paint tool. All I had was the zoom tool. Nothing is happening, someone please help.

Some effects including blur does not show it in OpenGL view (camera). You need either export to check in result or having a quick preview from Play>Quick Preview (shortcut Return). The quick preview shows in your web browser.