getting error while building and storing docker image using "az acr build --registry $REGISTRYNAME --image expressimage ."

Question

I am learning through "Microsoft Learn Challenge | Ignite Edition: Build AI apps with Microsoft Azure services" and I was following the Module instructions.
Build a Docker image and upload it to Azure Container Registry
Step1: creating Environment variable using**
# Set the registry name**

REGISTRYNAME={registry_name} //

# Set the resource group name

**RESOURCEGROUP=learn-cna-rg

Step2: git clone https://github.com/MicrosoftDocs/mslearn-cloud-native-apps-express.git
Step3:** change directory to the app and inside the src folder**
Step4:** Build and store the Docker image in your container registry using the az acr build command. Make sure to include the . at the end of the command.

       az acr build --registry $REGISTRYNAME --image expressimage .  

and then comes the error when I am executing the command. Got the below error what could be the reason?
"(TasksOperationsNotAllowed) ACR Tasks requests for the registry LearnAzure and f4799f09-4955-4a2d-ab13-283e0400abe1 are not permitted. Please file an Azure support request at http://aka.ms/azuresupport for assistance.

Code: TasksOperationsNotAllowed

Message: ACR Tasks requests for the registry LearnAzure and f4799f09-4955-4a2d-ab13-283e0400abe1 are not permitted. Please file an Azure support request at http://aka.ms/azuresupport for assistance.

Target: request"

Is this because I have a standard plan and this thing is not permitted in standard plan?