Need a help with a regex in the chat triggers

Hi, Zendesk Team!

I have added one widgets on two different sites:

example.com

anotherone.com

 

I have pages with a subscriptions:

example.com/billing

anotherone.com/pricing/

 

Now I want to create the trigger for to start chatting proactively if the visitor URL contains "billing" or "pricing".

 

So good news is that I am able to use regex, but what exact correct expression?

I tried the next expressions:

billing|pricing

/billing|pricing/

(billing|pricing)

/(billing|pricing)/

 

But anyone doesn't work for me.