Solution
In your LabVIEW Web Server, use the Set HTTP Header.vi to set the HTTP Header field "Access-Control-Allow-Origin". You could specify the allowed domain on its own, or choose the value "*" to allow any domain. Note that using the asterisk, “*”, to allow any domain has security implications that should be researched and reviewed before this solution is implemented.
Note: The LabVIEW Web Server is hosted in LabVIEW 2018 or compatible while the Web VI is built in LabVIEW NXG.