REST Linked Service configure dynamic session key

[KBD]

Hello: 

This question/posting provides more details:

pulling data from a REST API via Linked Service & ... - Microsoft Fabric Community

Futher experimenting has brought up more questions

I believe I need to configure my REST Linked service to be dynamic.  Configure Parameters 

that can be set at run tiime.

The REST API I am working with requires that I pass a session key on each call after login 

In Postman it looks like this:

The Authorization is dynamic and changes each run.

The posting:  pulling data from a REST API via Linked Service & ... - Microsoft Fabric Community

shows I have access to the REST API with the correct User Name and Password.

My Linked Service looks like this:  

As you can see, in the above, I created a parameter, session Key,  on the Linked Service.

And I create two Auth Headers,  Authorization & AuthHeader.  Believe I read somewhere

that Data Factory get confused when there is only one Auth Header.  

When I click on Value for Authorization I do NOT get an option for Dynamic content.

All the tutorials I have found state you use Dynamic content to point the Auth Header to the Parameters.

What is going on here?   What am I missing?

KD