Yes, you need Kubernetes manifests in the same project. Typically a Deployment-manifest and perhaps Service and Ingress as well if you want.
A Deployment-manifest can be generated with (using > to direct output to a file):
kubectl create deployment my-app --image=my-image --dry-run -o yaml > deployment.yaml
Note: There is a alpha feature flag --generate-manifests that might do this for you.
E.g. with
skaffold init --generate-manifests