xiuling Greetings!
Could you confirm if you have applied for GPT-4 model using this form https://aka.ms/oai/get-gpt4? Have you got the confirmation as well?
If you have applied and got it approved, you should be able to see the GPT-4 preview models in the Azure OpenAI studio under deploy models.
I suggest you, Please Contact application/subscription related issues to csgate@microsoft.com team.
Additionally, if you have a support plan you may file a support ticket here.
Do let us know if you need any further help.
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