Error "The access request broker service is disabled." (4379776)

RDP sessions using the SPS initiated workflow with SPS as RDP Gateway failed with the following error:

[TimeStamp] [SPS-Hostname] zorp/scb_rdp[1633]: scb.info(4): (svc/3yWnYQYDL2vMQhyHfnee9n/sps_initiated_policy:1:2/stub): Plugin(aa/SGAA/main.py): [ERROR] The access request broker service is disabled.; code=60711, data={"Code":60711,"Message":"The access request broker service is disabled.","InnerError":null}

Session Password Access Enabled is unchecked by default

In the Primary SPP Web UI:

Expand Security Policy management > Settings > Security Policy Settings > Please enable the check box Session Password Access Enabled