Google sheets API v4 permissions PERMISSION_DENIED error using POSTMAN

Question

Despite I am adding the service account to the google sheet "Share button", when I consume the following API:

https://sheets.googleapis.com/v4/spreadsheets/1ub32k-AtYExxxxhAXUUxxxxuk_oh0FmM1Wztr7_hs?key=AIzaSyDc_Qx7ViyQO-dTkE4tvJtE6w-9PueqjgE&includeGridData=true

I am facing the following error, so i do not know if I need to add certain permission or something like that:

{
    "error": {
        "code": 403,
        "message": "The caller does not have permission",
        "status": "PERMISSION_DENIED"
    }
}

Note: The API KEY it is modified in this entry in order to do not break the company security rules.