Due to a requirement to make the ManagePools service more secure, it now requires authentication and also requires a special permission which is only available to administrators by default.
From Pipeline Pilot 2020, the /scitegic/managepools REST service has been removed and replaced with /auth/managepools and /admin/managepools which now require the user accessing the server to have the Platform/Administration/ReadServerDiagnostics Pipeline Pilot permission. By default, this includes Admin Portal users and users who have been granted Professional Client Administration Mode access.
Unfortunately, this change was initially not reflected in the documentation but the BIOVIA Pipeline Pilot 2022 Server Deployment Guide has now been updated so that it shows the correct path for the 2022 release.