Hashicorp Vault Required Provider Configuration in Terraform

My GitLab CI pipeline terraform configuration requires a couple of required_provider blocks to be declared. These are “hashicorp/azuread” and “hashicorp/vault” and so in my provider.tf file, I have given the below declaration:

terraform {
    required_providers {
         azuread = {
                    source  = "hashicorp/azuread"
                    version = "~> 2.0.0"
         vault = {
                    source = "hashicorp/vault"
                    version = "~> 3.0.0"

When my GitLab pipeline runs the terraform plan stage however, it throws the following error:

Error: Invalid provider configuration

Provider "registry.terraform.io/hashicorp/vault" requires explicit configuraton. 
Add a provider block to the root module and configure the providers required 
arguments as described in the provider documentation.

I realise my required provider block for hashicorp/vault is incomplete/not properly configured but despite all my efforts to find an example of how it should be configured, I have simply run into a brick wall.

Any help with a very basic example would be greatly appreciated.

The simplest possible configuration would just be:

provider "vault" {}

You can find the documentation here: Terraform Registry