1. When follow the documentation to gather the must-gather of ODF operator, the doc suggest the following path:
registry.redhat.io/odf4/ocs-must-gather-rhel8:v<installed_version_ODF>
    
2. When use the path provide in the documentation on the command `oc admin`
$ oc adm must-gather --image=registry.redhat.io/odf4/ocs-must-gather-rhel8:v<installed_version_ODF>

3. The error is because the path is incorrect, for ODF-4.13 and above (Rebase to RHEL9).

e.g.
$ oc adm must-gather --image=registry.redhat.io/odf4/ocs-must-gather-rhel8:v4.13.7 --dest-dir=./ODF_MUST                                                                                                                          [must-gather      ] OUT Using must-gather plug-in image: registry.redhat.io/odf4/ocs-must-gather-rhel8:v4.13.7When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information:ClusterID: 446d88d9-5b1d-4ee4-89d0-ce318545e030ClusterVersion: Stable at "4.13.0"ClusterOperators: All healthy and stable [must-gather      ] OUT namespace/openshift-must-gather-2r95v created[must-gather      ] OUT clusterrolebinding.rbac.authorization.k8s.io/must-gather-d8z5b created[must-gather      ] OUT pod for plug-in image registry.redhat.io/odf4/ocs-must-gather-rhel8:v4.13.7 created[must-gather-8rqmw] OUT gather did not start: unable to pull image: ImagePullBackOff: Back-off pulling image "registry.redhat.io/odf4/ocs-must-gather-rhel8:v4.13.7"[must-gather      ] OUT namespace/openshift-must-gather-2r95v deleted[must-gather      ] OUT clusterrolebinding.rbac.authorization.k8s.io/must-gather-d8z5b deleted Error running must-gather collection:    gather did not start for pod must-gather-8rqmw: unable to pull image: ImagePullBackOff: Back-off pulling image "registry.redhat.io/odf4/ocs-must-gather-rhel8:v4.13.7" Falling back to `oc adm inspect clusteroperators.v1.config.openshift.io` to collect basic cluster information.     

$ oc adm must-gather --image=registry.redhat.io/odf4/odf-must-gather-rhel9:v4.13.7 --dest-dir=./ODF_MUST                                                                                                                          [must-gather      ] OUT Using must-gather plug-in image: registry.redhat.io/odf4/odf-must-gather-rhel9:v4.13.7When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information:ClusterID: 446d88d9-5b1d-4ee4-89d0-ce318545e030ClusterVersion: Stable at "4.13.0"ClusterOperators:	All healthy and stable

[must-gather      ] OUT namespace/openshift-must-gather-qf4k2 created[must-gather      ] OUT clusterrolebinding.rbac.authorization.k8s.io/must-gather-hx6wc created[must-gather      ] OUT pod for plug-in image registry.redhat.io/odf4/odf-must-gather-rhel9:v4.13.7 created[must-gather-vprn2] POD 2024-04-16T15:54:40.682844092Z checking for existing must-gather resource 

The correct information which should be post on the documentation is:
registry.redhat.io/odf4/odf-must-gather-rhel9:v<installed_version_ODF>