Issue Adding Web Page Information to Interesting Moment

I've set up Interesting Moments to run on every form fill on our website and want to include the web page that the form is filled out on (we use the same form in multiple places so I'm trying to give Sales a wider picture of the lead's key activities).

I updated the IM to be as follows:

However, after filling out the form to test, this is what shows in Marketo - it's not populating the Web Page:

My questions:

1. Is this the correct trigger I should be using to display the Page URL? I tried {{trigger.Name}} before but it populated the name of the form (assuming because that's the trigger for the IM)
2. This particular form is a pop up once the visitor clicks on the page CTA - would that prevent the web page trigger from working as intended?

Any help/insight is much appreciated and thanks in advance  😀