I'm trying to deploy a website with Kubernetes. While deploying I get this error:

[exec kubectl]: Error from server (Forbidden): error when retrieving current configuration of:
Resource: "certmanager.k8s.io/v1alpha1, Resource=certificates", GroupVersionKind: "certmanager.k8s.io/v1alpha1, Kind=Certificate"
Name: "mysite", Namespace: "mysite-com-9777808"
Object: &{map["apiVersion":"certmanager.k8s.io/v1alpha1" "kind":"Certificate" "metadata":map["name":"mysite" "namespace":"mysite-com-9777808" "annotations":map["kubectl.kubernetes.io/last-applied-configuration":""]] "spec":map["secretName":"mysite-cert" "acme":map["config":[map["domains":["mysite.com" "www.mysite.com"] "http01":map["ingressClass":"nginx"]]]] "dnsNames":["mysite.com" "www.mysite.com"] "issuerRef":map["kind":"ClusterIssuer" "name":"letsencrypt-production"]]]}
from server for: "/mase.ai/mysite.com/deployment/webapp.yml": certificates.certmanager.k8s.io "mysite" is forbidden: User "system:serviceaccount:mysite-com-9777808:mysite-com-9777808-service-account" cannot get certificates.certmanager.k8s.io in the namespace "mysite-com-9777808"

[deployment]: An error happend during the kubectl command.

Does maybe anybody has an idea what the problem could be? Any help is very appreciated!