Access token not working

So I'm implementing the zoho desk api in a self client using python and the requests module. This far, i've been able to create my access tokens, but they don't seem to work. The way I made it working is :

i set in different variables my client_id and my client_secret, I setup the authorization code via the developer portal to give the proper permissions and then I call them by doing :

response=requests.post("https://accounts.zoho.eu/oauth/v2/token",data={
            "code":code,
            "client_id":client_id,
            "client_secret":client_secret,
            "grant_type":"authorization_code"
        })

At this point, when I print the response it gives a correct access token.

The problem is, when I get this access token and I use it by example to list all tickets, the response it gives me is <Response [400]>, with no further details provided.
My question is, what am I doing wrong and how can I fix it ?