When I tried to register a new property using the Omeka S REST API, the following error occurred.

{ errors: { 'o:vocabulary': [ 'A vocabulary must be set.' ] } }

I then found the following thread, which mentions that adding properties through the REST API is not supported.

Programmatically adding properties with REST API
Hello, I would like to add properties to an existing vocabulary with the REST API, but donโ€™t understand how I must define the vocabulary in the payload. I tried this structure: { 'o:local_name': 'blablabla', 'o:label': 'blablabla', 'o:vocabulary': { 'o:id': <vocabulary_id> } } โ€ฆ but get the error: { errors: { 'o:vocabulary': [ 'A vocabulary must be set.' ] } } Thank you all for any help you can offer ๐Ÿ™‚
Omeka Forum

I hope this helps anyone else running into the same issue.