ZAPI not returning Execution ID

[MHayden]

I'm using ZAPI to update the execution status of a test case, however when I use this:

GET - http://localhost:8080/rest/zapi/latest/execution?issueId={id}

to get the execution id all that's being returned is the below, can anyone help? 

{"status":{"1":{"id":1,"color":"#75B000","description":"Test was executed and passed successfully.","name":"PASS"},"2":{"id":2,"color":"#CC3300","description":"Test was executed and failed.","name":"FAIL"},"3":{"id":3,"color":"#F2B000","description":"Test execution is a work-in-progress.","name":"WIP"},"4":{"id":4,"color":"#6693B0","description":"The test execution of this test was blocked for some reason.","name":"BLOCKED"},"-1":{"id":-1,"color":"#A0A0A0","description":"The test has not yet been executed.","name":"UNEXECUTED"}},"issueId":2915420,"executions":[],"currentlySelectedExecutionId":"","recordsCount":0}