Not possible. Domain model must be created.
May be you can also explain what you are trying to achieve, so experts in the forum might advice your differently.
UPDATE
After reading the latest comment from Alvaro:
- You cant create dynamic entities
- But you can create Objects for entities using microflow
- Use the create activity, select the entity, fill the attributes and associations, Commit
- You should also decide when you want to do this, for which refer https://forum.mendix.com/link/questions/95957
Hi Alvaro
Microflows define the logic of flow and it's for performing some actions on objects.
As simple as that
Entity is a class and objects can be created via microflows. So you are not able to create a new entity via microflow
https://docs.mendix.com/refguide/entities