How to fix 'Service and subscription limits' on PostgreSQL Fexible Server deployment using bicep file?

Question

tags: ResourceDeploymentFailure, PostgreSQL Fexible Server deployment, bicep file, MS Learn tutorial, Git cloned .../mslearn-postgresql.git

Exceptions support request with Issue type of 'Service and subscription limits'.

I cannot file Exception Support Request, as only with paying Support subscription is doable.

I followed MS Learn GITHUB tutorial reached through MS Learn tutorial on Azure AI Extension, used the defined settings, parameters, cloned the given MS Learn PosgreSQL module and then run the defined command:
az deployment group create --resource-group $RG_NAME --template-file "mslearn-postgresql/Allfiles/Labs/Shared/deploy.bicep" --parameters restore=false adminLogin=pgAdmin adminLoginPassword=$ADMIN_PASSWORD

ADMIN_PASSWORD and RG_NAME (includes Azure region name) were set previously as described in the tutorial.

I received this error:

{"status":"Failed","error":{"code":"DeploymentFailed","target":"/subscriptions/148212ea-cdcc-432d-a237-3e7a8934.../resourceGroups/rg-learn-postgresql-ai-eastus/providers/Microsoft.Resources/deployments/deploy","message":"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/arm-deployment-operations for usage details.","details": [{"code":"ResourceDeploymentFailure","target":"/subscriptions/148212ea-cdcc-432d-a237-3e7a8934.../resourceGroups/rg-learn-postgresql-ai-eastus/providers/Microsoft.DBforPostgreSQL/flexibleServers/psql-learn-eastus-sxqaulmhg3ddu","message":"The resource write operation failed to complete successfully, because it reached terminal provisioning state 'Failed'.","details": [{"code":"RegionIsOfferRestricted","message":"Subscriptions are restricted from provisioning in this region. Please choose a different region. For exceptions to this rule please open a support request with Issue type of 'Service and subscription limits'. See https://review.learn.microsoft.com/en-us/azure/postgresql/flexible-server/how-to-request-quota-increase for more details."}]}]}}

If I change the region (and consequently reset the parameters and everything) as suggested by some Community support pages and by Copilot, then I receive this error:

{"code": "InvalidTemplateDeployment", "message": "The template deployment 'deploy' is not valid according to the validation procedure. The tracking id is 'dbfe0b8f-a391-43dc-a25d-2b613ac7....'. See inner errors for details."} Inner Errors: {"code": "DeploymentModelNotSupported", "message": "The model Publisher: , Format: OpenAI, Name: text-embedding-ada-002, Version: 2, Source: , SourceAccount: is not supported in current region."}

So I cannot finish deployment and cannot continue my learning path.
I have a pay-as-you-go account (I updated yesterday, to avoid other blocking error).

Thank you for helping fixing this error!