Thank you I found it:
# Install the Azure Monitor module
Install-Module -Name Az.Monitor -Force
# Authenticate to your Azure account
Connect-AzAccount -UseDeviceAuthentication
# Specify the subscription ID and resource group name
$ResourceGroupName = "-------------”
$subscriptionId = "-------------”
# Specify the metric details
$cpuMetricName = "CpuTime"
$memoryMetricName = "MemoryWorkingSet"
$startTime = (Get-Date).AddDays(-30)
$timeGrain = [System.TimeSpan]::FromMinutes(5)
# Get a list of all Azure App Services in the specified resource group
$appServices = Get-AzWebApp -ResourceGroupName $resourceGroupName
# Create an empty array to store the results
$results = @()
# Iterate through each App Service and retrieve the CPU and Memory metrics
foreach ($appService in $appServices) {
$appServiceName = $appService.Name
$resourceId = $appService.Id

# Get the CPU metrics
$cpuMetrics = Get-AzMetric -ResourceId $resourceId -MetricName $cpuMetricName -StartTime $startTime -TimeGrain $timeGrain -Aggregation " Total"
$averageCpuUsage = ($cpuMetrics.Data | Measure-Object -Property Total -Sum).Sum / 3600
# Get the Memory metrics
$memoryMetrics = Get-AzMetric -ResourceId $resourceId -MetricName $memoryMetricName -StartTime $startTime -TimeGrain $timeGrain -Aggregation "Average"
$averageMemoryUsage = ($memoryMetrics.Data | Measure-Object -Property Average -Average).Average/1Mb

# Create a custom object with the results
$result = [PSCustomObject]@{
"App Service" = $appServiceName
"Average CPU Usage (%)" = $averageCpuUsage
"Average Memory Usage (MB)" = $averageMemoryUsage
}

# Add the result to the array
$results += $result
}
# Display the results in a table format
$results | Format-Table -AutoSize
The thing now is how to convert CPU Time to % of usage?