Yes, you can do a pop-up window in Wix. You can use the Wix Editor to add a pop-up window to your site.
To add a pop-up window, first add an HTML element to your page. Then, in the HTML element, add the following code:
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The code above will create a pop-up window that is 780px wide and 200px tall. You can change the width and height values to whatever you want.