Obtain the ServiceNow API full URL with crednetial informations

QRadar Log Source Configuration for servicenow as below 
If you want to ingest data from servicenow using Universal Rest API Protocol, configure a log source on the QRadar® Console using the Workflow field so that the defined servicenow isntance can communicate with QRadar by using the Universal Rest API protocol.

Log in to QRadar.
Click the Admin tab.
To open the app, click the QRadar Log Source Management app icon.
Click New Log Source > Single Log Source.
On the Select a Log Source Type page, Select a Log Source Type (Universal DSM) and click Select Protocol Type (Universal Rest API).
On the Select a Protocol Type page, select a protocol and click Configure Log Source Parameters.
On the Configure the Log Source parameters page, configure the log source parameters and click Configure Protocol Parameters.
On the Configure the Protocol Parameters page, configure the protocol-specific parameters (Workflow and Workflow Parameter Values).
In the Test protocol parameters window, click Start Test.
To fix any errors, click Configure Protocol Parameters. Configure the parameters and click Test Protocol Parameters.
Click Finish