How Aggregate ID will be Created after publishing the Command

I am trying to build Event Sourcing Command Model using Synapse. I am in confusion how the Agggregate Id Will be Created for the command once it was published through Provided Http request by synapse.
Here is the endpoint that I am refering{context}/commands

Please help me to understand, How the Aggregate will be created. Is it something I need to create explicitly, if so I didnt see any endpoint here Axon Synapse API.

Typically you want the aggregate id to be part of the command message. In de rust demo I modelled it like that. In the case it’s the initial command, you could generate the id. The problem is you need this is for any next commands.

Something to keep on mind, is that the aggregate id should be unique for the context. So if you have, for example, aggregates for employers and employees, and you use just the email as aggregate id, you can’t have both an employee aggregate and an employer aggregate with the same email. So it might be wise to prepend or appent that its either, so you can have this.