Send command at startup with mattermost operator

hello

i deploy mattermost on kubernetes with the operator

i need to launch a mmctl command in startup to change a plugin config
how should i proceed to put this in my :

apiVersion: installation.mattermost.com/v1beta1
kind: Mattermost
metadata:
name: metis # Chose the desired name
spec:
podExtensions:
initContainers:
- command:
- /bin/sh
- -c
- touch /etc/test2
image: busybox
name: hello

size: 100users # Adjust to your requirements
ingress:
enabled: true
host: xxxxxxx # Adjust to your domain
annotations:
kubernetes.io/ingress.class: nginx
version: 6.6.1