Not getting Cycle data from API calls

Trying to get cycleID's for our Zephyr Cloud using:

https://<jira_server>/rest/api/latest/cycle?projectId=10002&versionid=10003

I get 404 response.

/Project/10002 produces results as does /version/10003

we have cycles set up for Version 10003 eg: Unit Testing, Regression Testing, with test executions in them, but can't get them to show in the cycle? call.