Notification to assignee when there is an assignee being assigned for a test steps

Hi,

We have an E2E test cases, where in between there will be different assignees on testing steps. With that, we have created a custom field "Assignee" on the test scripts, to have this field appear on each of the test steps. It's working fine. However, the assignee has no idea that it's pending at his/her end to execute the test, therefore we wonder if there is any notification can be set to alert the assignee?

Thank you.