I think you made a mistake in the Request URL as it should be finalURL, not a “http://finalURL”
In the initialURL the variable should hold this value “http://my_endpoint…?caseNumber=”
Also, check if you need to specify some values in the Headers. For that, check the Headers in the Postman request.
Also, you may try to set the Enable SSL certificate verification to False.
Let us know if this helped.