Tweepy 403 Forbidden Error Trying to Read Data

Question

I am unable to read data from twitter using tweepy.

Hi there,

I am trying to read some data from twitter using tweepy.

Here is my very basic code:

import tweepy

consumer_key="xxx"
consumer_secret="xxx"
access_token="xxx"
access_token_secret="xxx"
bearer_token="xxx"


client = tweepy.Client( bearer_token=bearer_token, 
                        consumer_key=consumer_key, 
                        consumer_secret=consumer_secret, 
                        access_token=access_token, 
                        access_token_secret=access_token_secret, 
                        )

client.get_user(username = "Pontifex")

However I get this error, without further explanation: "tweepy.errors.Forbidden: 403 Forbidden"

I am confident that all the keys are correct.

My twitter app does not have user Authentication setup, because I only need to read data.

Any help is highly appreciated!