Helm chart: Why environment variable defined in values.yml of helm chart not added to generated manifest?

I am trying to add environment variable to my wordpress helm chart. My values.yml file looks like :

#pvc wordpresspersistence:  enabled: false#pvc mariadbmariadb:  enabled: false externalDatabase:  host: mysql  port: 3306  user: benighil@benighil   password: "SomePassword"  database: bitnami_wordpressextraEnv:  - name: "WORDPRESS_DATABASE_SSL_CA_FILE" # <== THIS ONE    value: /tmp/ca-cert## Additional volume mounts## Example: Mount CA fileextraVolumeMounts:  - name: ca-cert    mountPath: /tmp## Additional volumes## Example: Add secret volumeextraVolumes: - name: ca-cert   secret:     secretName: ca-cert

But i generate a template using the following cmd :

helm template wp azure-marketplace/wordpress -n app --create-namespace -f values.yml > template.yml

and when i search the word : WORDPRESS_DATABASE_SSL_CA_FILE in the file template.yml :

terminal: grep WORDPRESS_DATABASE_SSL_CA_FILE template.yml there is nothing returned !

I would like to know why ?

Thank you in advance!