Sharepoint app REST Authorization Header

I have developed a Sharepoint app that I installed on my sharepoint site for testing. I filled it with data and now I want to run REST queries on my app with Postman in Chrome.

Once I am logged in to my site in Chrome it works, but when I am not logged in I get Access Denied.

How do I fix this? Do I have to use the OAuth 1.0 for this? What should I put in the fields (Consumer Key, Consumer Secret, Token Key, Token Secret etc)?

Thanks for your help!