How to set/get a relation type to an CapellaIncoming/OutgoingRelation with Py4C

I succeeded in importing VP requirements from an excel file including CapellaIncomingRelation (idem pour Outgoing) with Py4C. Now, I would like to set a RelationType to a CapellaIncomingRelation. I don’t find any function in the class CapellaIncomingRelation. Could you help me?
here is a screenshot of the script and the Capella Test model :
se = model.get_system_engineering()
req = Requirement()

Thank You!

There is no API to set the relation type. You can use: