Dynamically populate permissible values for a Card or Phase drop-down field via API

We have a field on an external system which is a drop-down, for example;

UK Counties:

Avon

Carmarthenshire

etc

We want to ensure that the same field on a Pipefy Card has the same drop-down value list whenever the Card enters the Phase which has the County field.

Does the Pipefy API allow us to dynamically create the drop-down options for a “dropdown select” field. We can’t work that out from the API documentation, sorry!

Thanks