initialize-vault.sh

#!/bin/bash

export VAULT_ADDR="http://`juju run --unit vault/0 unit-get private-address`:8200"

VAULT_INIT="$(vault operator init -key-shares=3 -key-threshold=3)"

for KEY in $(echo $VAULT_INIT | grep "Unseal Key " | cut -d' ' -f4); do
    vault operator unseal $KEY
done

export VAULT_TOKEN=$(echo $VAULT_INIT | grep "Initial Root Token: " | awk '{print $4}')
MY_TOKEN=$(vault token create -ttl=10m | grep "token " | awk '{print $2}')
juju run-action --wait vault/leader authorize-charm token=$MY_TOKEN

There is this other script that allows you to do the same and it's maintained - https://github.com/canonical/stsstack-bundles/blob/main/tools/vault-unseal-and-authorise.sh