Problems accessing to a RDS through a Bastion Host from a local K3s

Question

I'm trying to build a local Kubernetes with K3s and I'm having problems to access to my RDD that is situated in the private Area of the VPN.

For now, I'm trying to deploy a Passbolt (https://artifacthub.io/packages/helm/cnieg/passbolt) and I'm following the steps to use my own database. Before the creation of the service, I've previously bind the port with the command:

ssh -i key.pem -L 1223:db:3306 user@BASTION -N -f

The service that I'm trying to use is:

apiVersion: v1
kind: Service
metadata:
  name: db-mysql
spec:
  selector:
    externalName: 10.0.2.2
    type: externalName
  ports:
  - protocol: TCP
    port: 3306
    targetPort: 1223

I'm getting this error:

Exception: There was a problem connecting to the database: SQLSTATE[HY000] [2002] Connection refused

Same if i try to use 127.0.0.1 instead of 10.0.2.2

Thanks!