Due to a limitation with redirects in the RA.Webservice REST it is not possible to natively trigger jobs through the REST API of SAP IBP.
See also here:
https://apps.support.sap.com/sap/support/knowledge/en/2584064
Instead of receiving the x-csrf-token and cookie a html body is received with the address of the SAML server.
Release : 12.3
Component : AUTOMATION ENGINE
The version of the REST interface integrated in the RA.REST cannot handle redirects to SAML
There are two possible workarounds:
https://stackoverflow.com/questions/56763018/is-there-a-way-to-retrieve-the-redirected-url-from-a-postman-response