Что касается проблемы, вы можете использовать Html Form для ее реализации.
Например
- Html page
<!DOCTYPE html>
<html>
<script type="text/javascript"
src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.4.1.js">
</script>
<body>
<form enctype="multipart/form-data">
<input name="file" type="file" />
<input type="button" value="Upload" />
</form>
<progress></progress>
<script language="javascript" type="text/javascript">
$(document).ready(function(){
$(':file').on('change', function () {
var file = this.files[0];
console.log(file)
$(':button').on('click', function () {
var form = new FormData()
form.append('file',file)
$.ajax({
// Your server script to process the upload
url: '<your azure function app url>',
type: 'POST',
crossDomain: true,
enctype: 'multipart/form-data',
// Form data
data:form,
// Tell jQuery not to process data or worry about content-type
// You *must* include these options!
cache: false,
contentType: false,
processData: false,
success : function(data){console.log(data);},
// Custom XMLHttpRequest
xhr: function () {
var myXhr = $.ajaxSettings.xhr();
if (myXhr.upload) {
// For handling the progress of the upload
myXhr.upload.addEventListener('progress', function (e) {
if (e.lengthComputable) {
$('progress').attr({
value: e.loaded,
max: e.total,
});
}
}, false);
}
return myXhr;
}
});
});
});
});
</script>
</body>
</html>
Код функции (загрузить файл в Azure blob)
import logging
import os
import azure.functions as func
from azure.storage.blob import BlobServiceClient, BlobClient
def main(req: func.HttpRequest) -> func.HttpResponse:
logging.info('Python HTTP trigger function processed a request.')
try:
file= req.files.get('file')
logging.info(file.filename)
connect_str="your storage account connection string"
container="your container name"
blob_service_client = BlobServiceClient.from_connection_string(connect_str)
blob_client =blob_service_client.get_blob_client(container=container,blob=file.filename)
blob_client.upload_blob(file)
except Exception as ex:
logging.info(ex.args)
return func.HttpResponse(f"the file {file.filename} upload successfully")
Настройка CORS для вашей функции 
Проверка 