This worked for me:
r = requests.post(f'{rooturl}/uploads.json',
files = {'files[]': (file, open(file, 'rb'), 'image/png')},
data={'type':'image'},
headers={
"Api-Username" : sys.argv[1],
"Api-Key" : sys.argv[2],
})
Probably, content-type': 'multipart/form-data'
should be omitted so the requests
library can figure out what to.