Hello,
To be able to edit the Contact Form Popup content, you need to edit your Contact Us page with the Page Builder active on your Site > if you are using WPBakery then you need to switch your editor style to Backend Editor in it > then scroll down to the button which is showing Popup > there you will see the Contact Form widget (in which you get to know the Contact Form being used in the Popup Content) and on the right of that you’ll get to edit the right most content of the Contact Form Popup. See this image from Test Site in this regard to get better understanding: https://postimg.cc/2qhShbCN
Best Regards
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