Implementing Audience manager through DTM

I am currently trying to deploy the following tools through DTM: 

• Adobe Target
• Adobe Audience Manager
• Adobe Marketing Visitor ID Service
• Adobe Analytics 

By using DTM, I am wanting to provide Audience manager with a prop value (for a visitor), and this prop value determines the Test and Target experience the visitor sees when they visit a test URL. 

The analytics is tracking a prop, i.e. prop1=test_value, and this is appearing correctly in the tracking as well as my test report suite. However, Audience manager is unable to find this prop and use it in order to determine the target audience. 

I was wondering if there is custom code that i need to implement in the DTM Audience manager tool in order to pass through the Analytics prop value through to the Audience tool? And if so, could i please get an example for what this code should look like? 

Thanks for any help