I'm in the Inspect Objects at Checkpoints step of the Developer Console Basics module, and I open the EmailMissionSpecialist class and set the Debug Log Level for ApexCode to Finest, but the line inspectResults(results); does not get marked as a checkpoint in the console (no red dot). When I run the execute anonymous command, no checkpoints are shown under the checkpoints tab.

Regarding the Unit, Inspect Objects at Checkpoint
https://trailhead.salesforce.com/developer_console/developer_console_checkpoints
 cant add a checkpoint on line no 13.

Can anyone please help?