Not allowed to upload this file type – REST API issue

Hi all, I’m having an issue and hoping someone can help.

I’m using WP REST API to try and upload a .csv file using Python. I have edited my wp-config file and functions.php file to allow csv files to be uploaded, and installed a MIME type plugin.

I can upload CSVs through the dashboard, but get this error when I try using Python:

{'code': 'rest_upload_sideload_error', 'message': 'Sorry, you are not allowed to upload this file type.', 'data': {'status': 500}}

Any ideas what could be happening here? My python is below:

user = 'myusername'
password = 'xyz'
url = 'https://localhost/enigma/wp-json/wp/v2/media'
creds = user + ':' + password
token = base64.b64encode(creds.encode())
csvname = "CSV File"
csvpath = "Weekly Highlights\csv-exports\hisorical_prices.csv"
csvbytes = {'file': open(csvpath, 'rb')}
header = {'Authorization': 'Basic ' + token.decode('utf-8'), "Accept": "application/json", "Content-type": "text/csv", 'Content-Disposition': "attachment; filename=%s" % csvname,}
post = requests.post(url, headers=header, files=csvbytes)
print(post.json())