Go to the "Test" tab of the API and copy the cURL example.
Run the cURL example in your terminal and copy the access_token from the response. The tool jq can be helpful for this.
In the example change <your tenant domain> on line 30 to the domain used in the cURL request.
Run the example with go run main.go.
In a new terminal use cURL to talk to the API: curl -v --request GET --url http://localhost:3000
Now try it again with the access_token you copied earlier and run curl -v --request GET --url http://localhost:3000 --header "authorization: Bearer $TOKEN" to see a successful request.