Unsure if "Does Microsoft's azure api exist?", means that a similar endpoint to Openai's realtime api exists? If yes, then sure, that exists. This can be found going from the documentation from Azure (depending on your use case).

If you're referring to the issue that deltas are received at the same point in time, as the transcription is completed, see this nice explanation on the issue:
https://learn.microsoft.com/en-us/answers/questions/5603828/no-user-transcription-deltas-from-azure-openai-rea
Basically: Currently there is an architectural difference between Azure OpenAI Realtime API and OpenAI Realtime API. This results in deltas not being received through Azure OAI Realtime API, whilst the transcription is running. Whereas, if you were to use OpenAI's realtime API directly, the deltas should be available during transcriptions.