@admin81489 Welp, it seems as if the issue isn’t fetch() , but rather the wixFormSubmitted() event handler isn’t being triggered.
You stated…
I copied the exact same code to my lightbox, since it has a form in it. The # of the form is “getDemoPopup”:
What form does the Lightbox have? Did you add a Wix Form ? How did you add the form and configure it? How does the form appear in the Lightbox? Does it have the same field names? (I know, I know, but I’m just checking to be sure)