Why do curly braces in utm tags turn into %7B?

Question

HTML

Links with dynamic tags that in curly brackets &utm_campaign=${UNIVERSAL_SITE_ID}
become &utm_campaign=%24%7BUNIVERSAL_SITE_ID%7D
This only happens on one site.
Tell me how to fix this?

Answer 1

This is XSS protection. To protect against inserting javascript scripts into url. It is better to come up with another way to obtain the information you need, but leave protection.