How do I change the city on my iPad World Clock widget in Lock Screen?

I am trying to change the city on my iPads lock screen widget for World Clock (official iOS clock app) but I can’t seem to figure out how. I have put the city that I want to be on the widget as the first city in my world clock, and deleted Cupertino from the world clock list in clock app. But it still shows Cupertino on the Widget. How do I change it?

[Re-Titled by Moderator]

Original Title: World clock clock screen widget on iPad