When there are no kafka topics in my namespace:

oc get kafkatopic         
No resources found in avano-syndesis namespace.

I can choose the any topic name when creating the integration:

and the topic will be created when the integration starts:

oc get kafkatopic
NAME        PARTITIONS   REPLICATION FACTOR
testtopic   1            1

When the topic already exist, when creating an integration, I can only choose previously created topic and create a new one anymore: