IG fulfillment thru REST API with Pre-emptive Basic Authentication

Hi All,

From IG fulfillment, trying to call the REST API with Pre-emptive Basic Authentication. Here is the sample REST API with pre-emptive authentication,

curl --location --request POST 'rpaoo.advantageinc.org:8443/.../executions' \
--header 'Content-Type: application/json' \
--header 'Authorization: Basic YWRtaW461234dARAWTIzNA==' \
--data-raw '
{"flowUuid": "0a5f5883-9b2f-4324-ab7b-356bcb2c59b1",
"inputs": {
"min":"1",
"max":"10"}
}'

When trying to call this REST API thru Postman/SOAP UI and even run the following in Linux OS, and able to receive the response. But when running this in IG fulfillment REST API call, receiving this error: " [com.netiq.iac.persistence.dcs.prov.worker.AutoProvisioningWorkerThread] [IG-DTP] Unexpected error while provisioning changeItem id: 96. Reason: HTTP error, status code is 400.