You are missing a number of parameters that you need. Also you really should create a new forum thread. This thread is dealing with Authorization Code Grant and you are using the Password Grant.
Please refer to the documentation for the [API Password Grant] (openemr/API_README.md at master · openemr/openemr · GitHub) for the parameters you need. If you continue to have issues, please open up a new forum thread as this thread is only relevant to the Authorization Code Grant.