How to wait and go to a new URL with Nightwatch JS

So the scenario is that I am clicking on a button, and a loading pop up is displayed. What I am trying to achieve is that I want to wait for 5 seconds when the waiting pop-up is displayed and then navigate to a different URL.

So, I used browser.pause(5000) after the click but I am getting an error as:

TypeError: Cannot read property 'indexOf' of null

I can't use the web element of the loading pop-up because if I do it manually the pop up never stays on screen for more than a second.