Injecting Vault Token After Authenication (vault k8s auth method, autounseal startegy)

I have two vaults, one running on a vm and one running on openshift using Vault’s Helm Chart v0.25 (Release v0.25.0 · hashicorp/vault-helm · GitHub).
I’ve defined a k8s auth method in the vm vault in order to authenticate the openshift vault for the purpose of using autounseal seal method with transit engine. I get the token after authenticating but I need to inject it as an environment variable for the openshift vault to be started and unsealed. I’m currently using an init container to fetch the token and write it to a shared volume with the main vault container. How do I inject the token, written in a file inside that volume, as an env var in the main vault container?
Pay attention that currenly I am not using CSI or Vault Injector Agent, just pure server settings enabled in the Helm values file.