Hi Dror Mikdash,
Thank you for reaching out to us on MS Q&A forum.
If the virtual machine size Standard_DS3_V2* is not available, you can select any other size listed in the Launch Exercise documentation as shown below:
Various subscriptions offer different VM size options. If you need to use the Standard_DS3_V2* VM size, you may need to switch to a subscription that supports it.
If you encounter any future issues, please feel free to contact us, and we will be pleased to assist you further.
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