How to run the Lead Territory Assignment process automatically

Summary:

Currently when a Lead record is created we are running the Lead Territory assignment process manually. The business case scenario is when a record gets created the territory assignment should take place immediately. From the Lead Processing Activities task, we have option to run the schedular process as immediately,repeats, and schedule date. However, when I use the Immediate option it runs once and stops the process. So again when another record is get created the process doesnt run again we need to run from task. So my query is how do we run the process immediately when the record is