Content-md5 error getting returned and i dont know why

Question

i'm pretty new to api programming and i'm currently stuck due to the Content-md5 not getting submitted properly. I've absolutely no clue how i should start working on it.

The api i'm trying to request is the newly published Datastore API from roblox.

headers = {'x-api-key' : API_KEY, 'Content-Type': 'application/octet-stream'}
params={"datastoreName" : "AmountDonatedStore", "entryKey" : str(user.id)+"-xp"}

r = requests.post("https://apis.roblox.com/datastores/v1/universes/3450454946/standard-datastores/datastore/entries/entry", headers=headers, params=params)

the error i'm getting is this one:

b'{"error":"INVALID_ARGUMENT","message":"Content-md5 header required.","errorDetails":[{"errorDetailType":"DatastoreErrorInfo","datastoreErrorCode":"ContentMd5Required"}]}'

thanks in advance for any help