Feature

o  A Feature object has a "type" member with the value "Feature".
o  A Feature object has a member with the name "geometry".  The value
   of the geometry member SHALL be either a Geometry object as
   defined above or, in the case that the Feature is unlocated, a
   JSON null value.
o  A Feature object has a member with the name "properties".  The
   value of the properties member is an object (any JSON object or a
   JSON null value).
o  If a Feature has a commonly used identifier, that identifier
   SHOULD be included as a member of the Feature object with the name
   "id", and the value of this member is either a JSON string or
   number.
 https://datatracker.ietf.org/doc/html/rfc7946#section-3.2