How to limit the domain that is allowed to access an azure resource

I write an app next js and deployed to vercel . however I used azure service called azure open ai . In the request I send on azure open ai in the header of the request contains the api key . I don't want the user to be able to get this api key and access the azure open ai by themselves. so i want to restrict by domain can access to azure open ai . please show me how to do it

OpenAI service has limited accessibility at this time, but from what I've been able to glean from Q&A the resource configuration is common to the Cognitive Services family and so supports configuring IP address restrictions and private vnet connectivity. If your calling service has a fixed IP, this should be sufficient, but you could also consider Application Gateway for awareness of DNS names as frontend filtering criteria.