To insert your API key on postman for MyDHL Express API, just make sure you insert the parameter "Authorization" under Headers with your respective API key as explained in the screenshot below. You don’t have to insert anything under Authorization.
Here, we need to send Authorization header as a "Authorization: Basic [Base64-encode(APIKEY:APISECRET)] "
There is also a second option: getting authorization with the DHL Express API. Under authorization, choose basic authentication and enter your API key and secret key in the fields of username and password. and then automatically encoded values appear under the headers.
