Requests keeps returning 403 status, even when following evey step from api documentation

Question

I'm trying to use Solarman API (which is a very simple API from this website) to make a simple request to access a token, but it keeps returning a 403 code. Am I doing something wrong ?

here's the code I'm trying:

import requests




url = 'https://api.solarmanpv.com/account/v1.0/token?appId='+appid+'&language=en'

params = {
    'accept': 'application/json',
    'appSecret': appsecret,
    'password': password,
    'username': username
    }


response = requests.request('POST',url,params=params)


print(response)

bellow, you can see how documentation demands the request

and the example given: