Please refer to the PLR workflow at the bottom of the page at the link: https://wwwin.cisco.com/c/cec/organizations/cisco-services/ts/tso/gtc/cin/agent/glo/ise.html

Hi,   Based on the screenshot, you have generated SLR auth code instead of PLR auth code. PLR auth code is much shorter, so you wouldn't face this issue if you generate PLR auth code.   Thanks, Hoonki