azure partner information powershell billing

azure_subscription_partner.ps1

function Get-AccessToken {
    $context = Get-AzContext
    $profile = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile
    $profileClient = New-Object -TypeName Microsoft.Azure.Commands.ResourceManager.Common.RMProfileClient -ArgumentList ($profile)
    $token = $profileClient.AcquireAccessToken($context.Subscription.TenantId)
    return $token.AccessToken
}
function Get-AzSubscriptionPartner {
    param(
    [Parameter(Mandatory = $true)]
    [string]$subscription
    )
    $access_token = Get-AccessToken
    $headers = @{"Authorization" = "Bearer $access_token"; "Accept" = "application/json" };
    $url = "https://bmxservice.trafficmanager.net/api/Billing/Subscription/GetPartnerInformation?api-version=2019-01-14&subscriptionGuid=$subscription"
    $response = (Invoke-WebRequest -Method GET -Uri $url -ContentType "application/json" -Headers $headers).Content|ConvertFrom-Json
    Select-Object @{n='Subscription';e={$subscription}},@{n='PartnerId';e={$response.partnerId}},@{n='PartnerName';e={$response.partnerName}} -InputObject ''
}
function Set-AzSubscriptionPartner {
    param(
    [Parameter(Mandatory = $true)]
    [string]$subscription,
    [Parameter(Mandatory = $true)]
    [string]$partnerid
    )
    $access_token = Get-AccessToken
    $headers = @{"Authorization" = "Bearer $access_token"; "Accept" = "application/json" };
    $url = "https://bmxservice.trafficmanager.net/api/Billing/Subscription/SetPartnerInformation?api-version=2019-01-14"
    $data = @{
    subscriptionGuid = $subscription
    partnerId = $partnerid
    }
    $json = $data | ConvertTo-Json
    $response = (Invoke-WebRequest -Method POST -Uri $url -ContentType "application/json" -Headers $headers -body $json).StatusCode
    Select-Object @{n='Subscription';e={$subscription}},@{n='StatusCode';e={$response}} -InputObject ''
}

This code doesn't work, the token built from $context does not have permission to set Partner Id