Equivalent of HTML Markup control from Page Composer in Redwood ?

Summary: How to embed some javascript extension in Redwood (possible with Page Composer) ?

Content (please ensure you mask any confidential information):

With Page Composer, we used to be able to embed some javascript using HTML Markup control in page composer. Some 3rd parties tools have leveraged this capacity to include external guided learning capacities for example. With this move to Redwood, this option is no longer available and I would like to understand which alternative you would recommend to achieve a similar behavior ?

Version (include the version you are using, if applicable): 24A

Code Snippet (add any code snippets that support your topic, if applicable):