Accessing Jira REST endpoints

I have a local installation of Jira server and I want to access it’s endpoints. I installed the sample Kanban software development project during initial setup. The REST API docs show this example:

curl -u admin:admin http://localhost:8080/jira/rest/api/2/issue/KAN-1

The KAN-1 issue exists in the sample Kanban project. Executing this command returns json which says Oops, you've found a dead link.

What is the correct way to access the REST endpoints?

Also, do the Jira REST endpoints have a Swagger page?

Try:
http://localhost:8080/rest/api/2/issue/KAN-1
http://localhost:2990/jira/rest/api/2/issue/KAN-1
http://localhost:2990/rest/api/2/issue/KAN-1