[Python] Azure Speech to Text API using file in blob storage- 415 response Unsupported Media...

I am trying to run the Azure speech to text resource on some audio held in blob storage, so I have a python program that creates the file in blob storage and then attempts to run the speech resource on the file, but I keep getting a 415 response and the response content is just "b''", so Im having trouble figuring out what is wrong below is my request code

resp = requests.post(
url,
data={
"displayName": filename,
"locale": "en-GB",
"contentContainerUrl": container_uri,
"ContentUrls": [content_uri],
"properties": {
"diarizationEnabled": False,
"wordLevelTimestampsEnabled": False,
"punctuationMode": "DictatedAndAutomatic",
"profanityFilterMode": "Masked"
}
},
headers={"Ocp-Apim-Subscription-Key": sub_key, "Content-Type": "application/json"}
)


and here is the response

displayName: Recording.wav
Content container url:https://RESOURCE.blob.core.windows.net
contents url: https://RESOURCE.blob.core.windows.net/cnnn-blob/Recording.wav
<Response [415]>
response content: b''


I have searched around for people with similar problems, but theyre accessing different resources, and what worked for them (specifying content type, changing authorization method) isnt working for me. I have also tried uploading the same file converted to different file types, but I dont think the target file is the issue, as the 415 refers to the request itself right?

Continue reading...