BiologicallyDerivedProduct on the FHIR specification website.

A material substance originating from a biological entity intended to be transplanted or infused
into another (possibly the same) biological entity.

The body should be a list of valid JSON patches for BiologicallyDerivedProduct. For example, to update a Slot status to busy, this would be the body:

[
  {
    op: 'replace',
    path: '/status',
    value: 'busy',
  },
],