When I tried creating a compute engine using command gcloud compute instances create myVM

When I tried creating a compute engine using command "gcloud compute instances create myVM" and selecting zone [europe-west1-b], I am getting the following error:

ERROR: (gcloud.compute.instances.create) Could not fetch resource:

• Invalid value for field ‘resource.name’: ‘myVM’. Must be a match of regex ‘(?:a-z?)’