If you are trying to get a token from iRPA (SAP) this site might help you further: https://help.sap.com/viewer/d95546360fea44988eb614718ff7e959/Cloud/en-US/f891afcaae9b40d3aa23d7be8ae08371.html
From a quick scan this requires basic authentication and different payload, the site has some postman files available to see how this would work in a REST client.
Specify the variable of your exportmapping. Probably Root.
Here are the screenhots of my problem: