I am trying to a refresh on a single table in Azure Analysis services using PowerShell and Automation Runbook.
I am passing a bearer token to the header body but while testing it I am getting below error.
Response status code does not indicate success: 415 (Unsupported Media Type)

<#param
(
    [Parameter (Mandatory = $false)]
    [object] $WebhookData,

    [Parameter (Mandatory = $false)]
    [String] $DatabaseName,
    [Parameter (Mandatory = $false)]
    [String] $AnalysisServer,
    [Parameter (Mandatory = $false)]
    [String] $RefreshType
)#>

$AnalysisServer = "centralus.asazure.windows.net/servers/shipbobanalysisserver01/models"


$DatabaseName = "POC Shipbob TabularModel/refreshes"


$userName = $Credential.UserName
$securePassword = $Credential.Password
$password = $Credential.GetNetworkCredential().Password

$tenantId = ".........................................."
$requestAccessTokenUri  = "https://login.microsoftonline.com/$tenantId/oauth2/token"
$resource = 'https://centralus.asazure.windows.net/'
$pass = "..................................."

$requestBody = "grant_type=client_credentials&client_id=$userName&client_secret=$pass&resource=$resource"

$token = Invoke-RestMethod -Method Post -Uri $requestAccessTokenUri -Body $requestBody -ContentType 'application/x-www-form-urlencoded'

#Write-Output $token


$header=@{
"ContentType"="application/json"
"Authorization"="Bearer $($token.access_token)"
"Accept"="application/json"}


$baseUrl = "https://"+$AnalysisServer+"/"+$DatabaseName


$body =
'{
    "Type": "Full",
    "CommitMode": "transactional",
    "MaxParallelism": 2,
    "RetryCount": 2,
    "Objects": [
        {
            "table": "Hist_ShipbobLive_dbo_FulfillmentCenterType",
            "partition": "Partition"
        }
    ]
}'


Invoke-WebRequest -Uri $baseUrl -Body $body -Headers $header -Method Post -ContentType "aapplication/json"

Can someone please help in debugging this code.

I have tried to get the details of the error by using -Errorvariable RespErr and -SkipHTTPErrorCheck but found no luck.