Use Zephyr Scale Cloud API to add existing test cases to and newly created test cycle.

I am attempting to do this via powershell script in teamcity but I am getting a 404 when it attempts to add the testcase to the testcycle. I cannot for the life of me figure out why it is not working. any help is appreciated.

# -----------------------------
# Create test cycle
# -----------------------------

try {
    $createResp = Invoke-RestMethod -Uri $TestCycleEndpoint -Method POST -Headers $headers -Body ($body | ConvertTo-Json -Depth 5)
    $testCycleKey = $createResp.key
    Write-Host "✅ Created Zephyr Scale test cycle: $testCycleKey (linked to $($env:ZS_LINKED_ISSUE))"
} catch {
    $errResponse = $_.Exception.Response
    if ($errResponse -ne $null) {
        $reader = New-Object System.IO.StreamReader($errResponse.GetResponseStream())
        $responseBody = $reader.ReadToEnd()
        Write-Error "❌ Failed to create Zephyr Scale test cycle: $($_.Exception.Message)`nResponse: $responseBody"
    } else {
        Write-Error "❌ Failed: $($_.Exception.Message)"
    }
    exit 1
}

# -----------------------------
# Add mapped test cases to the cycle
# -----------------------------
$cycleTestCases = @()

foreach ($rxName in $TestCaseMapping.Keys) {
    $cycleTestCases += @{ testCaseKey = $TestCaseMapping[$rxName] }
}

$addCasesEndpoint = "https://api.zephyrscale.smartbear.com/v2/testcycles/$testCycleKey/testcases"
$addCasesBody = @{
    items = $cycleTestCases
}

try {
    Invoke-RestMethod -Uri $addCasesEndpoint -Method POST -Headers $headers -Body ($addCasesBody | ConvertTo-Json -Depth 5 -Compress)
    Write-Host "✅ Added $($cycleTestCases.Count) test cases into cycle $testCycleKey"
} catch {
    Write-Error "❌ Failed to add test cases into cycle ${testCycleKey}: $($_.Exception.Message)"
    exit 1
}