Before applying replace the secret with the actual one.

For debugging add `- --log-level=debug`:

```
wget https://raw.githubusercontent.com/kubernetes-sigs/external-dns/master/docs/contributing/crd-source/crd-manifest.yaml -O crd.yml
kubectl apply -n external-dns -f application.yml -f crd.yml
```

Insert TSIG secret:

```
 kubectl -n external-dns create secret generic tsig-secret \
    --from-literal=TSIG_SECRET=<secret>
```