If you are using Workflow, you would use an "IF" activity that looks at the variable to determine if the task should be created. If yes, use the "Create Catalog Task" activity. If not, continue on in the Workflow.
If you are using Flows, you would do the same thing, but you would use actions instead. First, get the variables via flow action, then look at the particular variable you need to evaluate, and finally if the value of the variable is right, create a catalog task with the pertinent details.
