The feature was announced[1] for OCP 4.10, is not working[2] with OCP 4.10 and not planned to be fixed[3][4] for OCP 4.10.

Please adjust the documentation[1].
Thanks

References:
1) 1.3.4.4. Running a pod in debug mode
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.10/html-single/release_notes/index#pod-debug-mode-web-console
2) "Debug container" in Web Console fails with "pods ... not found" or "The debug pod failed"
https://bugzilla.redhat.com/show_bug.cgi?id=2068047
3) RH internal: Errors trying to use the Debug Container feature
https://issues.redhat.com/browse/OCPBUGS-9795
4) [release-4.10] Bug 2069730: Remove duplicate app label on debug terminal
https://github.com/openshift/console/pull/11250