Cannot create app user for web application

Hi,

I have set up my web application to authenticate to Box using JWT, and I'd like to add an app user. However, whenever I try to do this from my code, I receive errors of invalid parameters. 

My request (in python) looks like this:

# jwt_header = {
#     'authorization': "Bearer " + token
# }
# url ="https://api.box.com/2.0/users"
# data = dumps({'name': 'My User', 'is_platform_access_only': True})
# response = requests.request(method="POST", url=url, data=data, headers=jwt_header)

What is wrong with the formatting of this request? 

However, when I do the same request from Postman, inputting 

{'name': 'My User', 'is_platform_access_only': True}

as "raw" into the Body, I receive an error "The request requires higher privileges than provided by the access token." I am a co-admin in my enterprise, what specific permissions do I need to create an app user?

To be clear, the application is under my account (within the enterprise).

Thank you!