What is the proper method to use a custom JavaScript variable to extract the inner text of a DOM element that might not exist yet?

To extract the inner text of a DOM (Document Object Model) element using a custom JavaScript variable in Google Tag Manager (GTM) when the element might not exist yet, you must use a combination of error handling and delayed execution. First, create a custom JavaScript variable in GTM. Inside the JavaScript code for the variable, use the `document.querySelector()` method to attempt to select the DOM element. Because the element may not exist immediately, wrap the `querySelector()` call in a `try...catch` block to handle potential errors. ....