Clarification of field "id" in API needed

[Hannah-Doerpholz]

I was trying today to work out how your API works using the webpage. However, to me it is not at all clear what input is expected in the "id" field. For example, at the moment I want to retrieve all parent terms of the term http://purl.obolibrary.org/obo/ENVO_01000263, using /api/ontologies/{onto}/terms{id}/ancestors. However, I can't seem to get the input for the id field right. My input for the "onto" field is "envo". So far I have tried "http://purl.obolibrary.org/obo/ENVO_01000263", "ENVO_01000263", "ENVO:01000263" and "01000263" for the id field, but none of them seem to work correctly. Could you clarify exactly what kind of input is needed here?