Two valid options for obtaining kubectl config file in Tanzu Kubernetes environment are:

Download from vSphere UI: For Tanzu Kubernetes clusters that are deployed on vSphere with Tanzu, you can download the kubeconfig file from the vSphere UI by selecting the cluster and clicking on the Download kubeconfig button1. This file contains the credentials and connection information for the cluster, which you can use to access it with kubectl1.

Access from VMware Tanzu Mission Control: For Tanzu Kubernetes clusters that are attached or provisioned by VMware Tanzu Mission Control, you can access the kubeconfig file from the Tanzu Mission Control console by selecting the cluster and clicking on the Access this cluster button2. This will generate a YAML file that you can download and use to connect to the cluster with kubectl2.

References: Download a Kubeconfig File for a Tanzu Kubernetes Cluster - VMware Docs, Connect to a Managed Cluster with kubectl - VMware Docs