Javascript or jQuery must first be placed inside a "newpage event" when adding to Lay Theme https://laytheme.com/documentation.html#custom-javascript
Newpage Events
Because your Lay Theme website is a "Single Page" JavaScript application you cannot just use jQuery(document).ready(…) to execute your js because the ready event only fires once when the website loads the first time.
window.laytheme.on("newpageshown", function(layoutObj, type, obj){ // your code would go here }); layoutObj is a an empty object. This used to contain the - layout's JSON, but was deprecated. type can be either "project", "page" or "category". obj is WordPress' post, page or term object. These objects contain general information like ids and slugs.Since Lay Theme 1.056 you can use a JavaScript event to execute your own JavaScript whenever a project, page or category is visited. The event is called "newpageshown". It will trigger when a new project, page or category has rendered.
Any jQuery '$' symbols must be written in full "jQuery" e.g
$(addClass); becomes jQuery(addClass);
Custom Code is most likely to be placed in "Custom <head> Content" in > Lay Options > Custom CSS & HTML >
Best wishes Lorenzo & have a great day 🏖 Richard