Add a textarea with up to at least 500-1000 rows for adding scripts

Having the ability to measure the use of the system, for setting a heatmap tracker etc, having different kinds of web metrics systems (public authorities in the EU usually do not use Google Tag Manager, Google Analytics etc since these tools send sensitive information to servers in the United States), I would like to see that I was able to add (per agency account, or if overridden at a customer account) any kinds of Javascripts to be able to e.g. set a chatbot, add web metrics, a heatmap tracker etc.