Release pipeline publish PowerBI report Azure DevOps failed at update datasource credentials

Hello,

I am trying to set up a release pipeline in Azure DevOps to publish a PowerBI report. I followed this instruction: https://community.powerbi.com/t5/Webinars-and-Video-Gallery/CICD-Pipeline-for-PowerBI-Reports-Azure-DevOps/td-p/864450

and it all worked fine. 

However, I have added a second datasource to my report and now I can't get the pipeline to run. It keeps failing at the 'update datasource credentials' task. 

The first datasource is an Azure SQL database (credentialType = 'basic'). The second datasource is an Azure blob-storage (credentialType ='key').

Is it possible to use differente datasources and how do I update the credentials for the second datasource? I have tried to get it to work with only the blob-storage source, but that didn't work either. 

This is the Powershell code I use with only one datasource:

$workspacename="workspace"
$datasetname="dataset" 

## user credentials
$clientsec = "$(client_secret)" | ConvertTo-SecureString -AsPlainText -Force
$credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $env:client_id, $clientsec 
Connect-PowerBIServiceAccount -ServicePrincipal -Credential $credential -TenantId $env:tenant_id

##Getworksapce
$workspace =Get-PowerBIWorkspace -Name $workspacename

## GetDataSets
$DatasetResponse=Invoke-PowerBIRestMethod -Url "groups/$($workspace.id)/datasets" -Method Get | ConvertFrom-Json

## Get DataSet
$datasets = $DatasetResponse.value

     foreach($dataset in $datasets){
                if($dataset.name -eq $datasetname){
                $datasetid= $dataset.id;
                break;
                }
            }
Invoke-PowerBIRestMethod -Url "groups/$($workspace.id)/datasets/$($datasetid)/Default.TakeOver" -Method Post

## update data source credentials
$BoundGateway=Invoke-PowerBIRestMethod -Url "groups/$($workspace.id)/datasets/$($datasetid)/Default.GetBoundGatewayDataSources" -Method GET | ConvertFrom-Json 

$UpdateUserCredential = @{
            credentialType ="Basic"
            basicCredentials = @{            
            username= '$(username)'
            password= '$(secret)'
            }
} | ConvertTo-Json

$response=Invoke-PowerBIRestMethod -Url "gateways/$($BoundGateway.value.gatewayId)/datasources/$($BoundGateway.value.id)" -Method PATCH -Body $UpdateUserCredential | ConvertFrom-Json