Hello @Xiaohua He Thank you for posting your question on the Microsoft Q&A platform. Apologies for the delayed response!
From the title of the post, I understand that you are unable to select free tier in the pricing type. You also mentioned that "deleted this resource and resource groups".
You can try to purge the deleted resource and check again - Recover or purge deleted Azure AI services resources - Azure AI services | Microsoft Learn
If there is a resource to purge, it will show up when you click manage deleted resources.
Hope this helps. Let us know how it goes!
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