1) First, I create a backup copy job that save backups on the NAS 1 in the production environment.
The first Job is called „Backup Job“. Or do you have another storage where you put the backups with a backup job and then you want todo a backup copy Job to NAS1.
2) Then I manually copy on an external USB drive to transfer the backup from the NAS 1 to the NAS 2 in the offsite Lab enviroment.
Why copying it manually? You could use a copy Job with Veeam. Then you will always have the newest restore points on the NAS2. Or is this testing a one time thing?
I don‘t see the advantage of an isolated test environment for only testing if backups will boot in a DR scenario.
Would that be my environment, without a paid license, I would start all vms with a few clicks in a instant vm recovery session connected to a isolated vswitch. Your approach will require a lot more manual intervention.
Obviously I must have in the offsite LAB environment a working copy o Veeam B&R (and for this purpose a Veeam Community Edition free, is suffient ?)
With the community edition, you can use the manual verification link from my first post. But If this backups, you want to test, are customer vms (Third Party data), you are forbidden to use the community edition. You should have a installed license (rental, if it‘s in your datacenter).