This size is currently unavailable in westeurope for this subscription: NotAvailableForSubscription.

NotAvailableForSubscription means the VM size is blocked for that subscription in the selected region. This is different from quota being available.

For a new Azure Free Trial subscription, this usually happens because some VM SKUs are restricted for the subscription or there is limited capacity in that region.

Try this:

1. Check which VM sizes are actually available in the target region. Use Azure CLI:

      az vm list-skus --location westeurope --resource-type virtualMachines --all --output table
   

   If a size shows NotAvailableForSubscription, it can't be deployed in that region for the subscription.
2. Try a different region and verify availability before deploying. Example:

      az vm list-skus --location northeurope --resource-type virtualMachines --all --output table
   

3. In the Azure portal, start creating a VM and open the Size picker. Select See all sizes to view the sizes currently available for that subscription and region. This does not require completing the deployment.
4. Prefer newer VM generations if older ones are unavailable. Community guidance in similar cases recommends trying newer series instead of older restricted ones.
5. If the required VM size or region is still blocked, submit a SKU request to Azure Support. The documented resolution for a SKU that is unavailable for the subscription in the needed region is to submit a support request.

If the same error happens for many sizes across many regions, that points to a subscription-level restriction rather than a VM configuration problem.

References:

• Resolve errors for SKU not available
• Unable to Create Any VM on Azure Free Trial - NotAvailableForSubscription Error - Microsoft Q&A
• Can't Create B1s Virtual Machine while Azure for Student Subsctiption is Activated - Microsoft Q&A