Hello,
Velero is not currently available as a license/supported product with OpenShift. If you are interested in using Velero with OpenShift, there are a few upstream community driven efforts to install Velero with an OpenShift enabled plugin to support backup/restore of OCP specific resources.
To do this, you can use a project called OADP which is an operator that can install Velero with the required OpenShift plugin. OADP is available in the community operators section of OpenShift and the instructions can be found here:
https://github.com/konveyor/oadp-operator/#getting-started-with-basic-install-olmoperatorhub. There are also instructions below there to install outside of OLM as well if you are interested.
If you want to install Velero yourself, then you can use the OpenShift plugin found here:
https://github.com/konveyor/openshift-velero-plugin.
Please let me know if you have any other questions,
Dylan