Self-signed TLS in k8s

Install/Maintain/Configure
1

Hello, I apologize for maybe annoyingly dumb question, but how do I enable TLS in k8s ingress with cert-manager (self-signed)?

gitea:
  config:
    server:
      ROOT_URL: https://git.example.com
ingress:
  annotations: {}
  enabled: true
  hosts:
    - host: git.example.com
      paths:
        - path: /
          pathType: Prefix
  tls:
    - hosts:
        - git.example.com
      secretName: chart-example-tls