It seems you are referring to the legacy integration of AAM and Target. There is now a much more robust and efficient option that connect Target and AAM with a server-side integration. You do need to implement the Marketing Cloud ID Service on your site to have this enabled though. Here's the documentation on setting up the MC ID Service. https://marketing.adobe.com/resources/help/en_US/mcvid/
If you really want to use the older client side integration I could dig around and try to find that old plugin for you.
Thanks for the response Ryan. We have a MC ID service setup done via DTM and we are using multiple tools from the marketing cloud.
Can you let me know how can we enable the server-side integration?
You need to request the provisioning from Adobe. I'd ask your consultant or Clientcare to help you make this provision request. You need to request the "Profiles and Audiences" integration be setup for your Marketing Cloud org.
Also we are trying to Integrate Data Workbench with Target and there are two methods. One is legacy method and other is using MMP with Marketing cloud. Do you mind sharing the advantage of legacy method v/s MMP approach? A list of pros/cons for both should be helpful.