Here are some notes which apply to all API calls:

Null values, empty strings and missing attributes are treated the same way, as setting the value to null. The only exception is Patch requests, where a missing attribute is considered unchanged.
If an attribute value is null / blank it will not be returned in Json responses.
All time stamp fields are expressed in UTC with timezone, for example "2022-05-18T14:53:00Z".
Additional attributes and statuses may be added and returned in Json responses without notice, so the website must allow this.
Passing in an unrecognized attribute in the body will generate an error