Hmmm…even I am a newbie to coding so forgive me if I can’t help you. But use “let” instead of “const”. Also let us make a distinction between the variable “EngMap” and the field title “EngMap”. So this will be in your code panel:
$w.onReady(function () {
//To load the page before running the code
$w("#dynamicDataset").onReady(function () {
//To load the dynamic dataset's data before running the following code
let EngMapVar = $w('#dynamicDataset').getCurrentItem().EngMap;
//we create a variable, NOT a CONSTANT, called "EngMapVar" and set its value to the URL we have //put in our data collection. Make sure "EngMap" is a URL type field in your data collection //containing URLs only!I think even that can be generating the error you are seeing in red. Not //sure though.
$w("#html4").src = EngMapVar;
//We set the html4's value to that of "EngMapVar".
})
});