How to export Variables and pass it on to your application deployment

Hi ,
I have configured vault and created a db secrets in it and is using it in my application deployment . i have the following annotations set in my app deployment

  annotations:
    vault.hashicorp.com/agent-inject: 'true'
    vault.hashicorp.com/agent-init-first: "true"
    vault.hashicorp.com/role: 'internal-app'
    vault.hashicorp.com/agent-inject-secret-database-config.txt: 'internal/data/database/config'
    vault.hashicorp.com/agent-inject-template-database-config.txt: |
      {{`{{- with secret "internal/data/database/config" -}}
        #!/bin/bash
        export DB_PASSWORD="{{ .Data.data.db_password }}"
      {{- end }}`}}

the export value is not getting reflected in my app deployment ( which i am installing using helm )
Apart from the export in the annotations do i need to update anything else .
The details are getting written on to the file system under a defined path in my app deployment as well .
but what i am looking is to set and pass it on to my app deployment rather than reading it from file system and then passing it on
Any details , highly appreciate