Wix
Use the “Embed HTML” (Custom Element) widget. Paste both the script and button code inside the embed block.
Wix limitation: Wix sandboxes custom HTML inside its own iframe, which means the overlay will open within the embed area rather than full-screen. This is a Wix platform constraint.
Squarespace
Script: Go to Settings → Advanced → Code Injection and paste the script tag in the Footer section.
Button: Use a Code Block on the relevant page and paste the button code.
