Get access to the Twitter API: https://developer.twitter.com/en/apply-for-access
Create an APP, as documented here: https://developer.twitter.com/en/apps
Click on “Details”, then “Keys and tokens”
(The credentials listed above will not work)
Use the generated credentials as below:
So where did the URL in GET come from?
The API Reference contains these instructions: https://developer.twitter.com/en/docs/tweets/timelines/api-reference/get-statuses-home_timeline