How to create a Connector using REST URL having headers?

Summary

How to create a Connector using REST URL having headers?

Content

I have a REST URL(ISG) that has header parameters.How can I create a REST connector using that REST URL in oracle MCS.

The REST URL is POST method and have 5 header parameters.

please clarify me below

1)where I have to attach the headers of rest URL (in rules or during testing endpoint)

2)If in testing endpoint means I have to add headers in my custom api  using Node js?

Now,I have added headers in Rules,while Testing endpoint it says authentication error so I added headers there also. Now I get 415 error code.