I have a Backlog as

The sprint 1 and sprint 2 are created by Create sprint API:
https://developer.atlassian.com/cloud/jira/software/rest/api-group-sprint/#api-rest-agile-1-0-sprint-post
The AW Board Sprint 1 is the default area.
When I click Start sprint button in sprint 1, it been copied to Board menu as

But when I get sprint with API like:
- https://my-domain.atlassian.net/rest/agile/1.0/sprint/1
It returned
{
"id": 1,
"self": "https://my-domain.atlassian.net/rest/agile/1.0/sprint/1",
"state": "future",
"name": "AW Board Sprint 1",
"createdDate": "2024-04-10T01:01:01.873Z",
"originBoardId": 1,
"goal": ""
}These APIs returned error:
- https://my-domain.atlassian.net/rest/agile/1.0/sprint/2
- https://my-domain.atlassian.net/rest/agile/1.0/sprint/3
{
"errorMessages": [
"We could not find the sprint"
],
"errors": {}
}Why can't get the created 2 sprints by API? And which API can be used to get the current ongoing sprint in Board?