I'd like to do schema markup for my wordpress blog in Google Tag Manager. I've integrated the variables for Image url and Date Published into my JSON-LD GTM Tag, but I get an error in the Google Structured Data Testing Tool saying:
url - false (The value provided for image.url must be a valid URL.)
datePublished - false (Cannot understand the value false as a date/time. Learn more about date/time formats.)
Can you please help me to find out what do I do wrong?