Send e-Mail to assignee with Automation

[Blake]

Hello,

we are using JIRA Server atm and can us automation,

In my case I want an e-Mail sent to an asignee of an issue if the issue breaches an SLA.

However, on the "THEN" when I select "Send e-Mail" I can only select "Reporter (customer" and "Customers involved".

Is there any option how I can notify the assignee of the issue, not the customer? Or is the assignee getting an e-Mail automatically in case of a SLA breach?

Screenshots is in the comments.

[Blake]