This article will walk you through how to search for your callbacks on the agent page. 

Click on the Folder Icon found in the upper left side of the agent interface, this will open the CRM.

Click on Callback Tab. This will show the list of callbacks.

Click on the lead and it will open up the lead's information.  When in a not ready status, click the red phone to make a manual call. 

Note: If the lead were deleted by the Admin and it was tagged as Callback, it will no longer show on the Agent's Callbacks tab as well as on the Callbacks section on the Admin side.