Enable Debug Mode in Salesforce
To enable debug mode for users in your org:
In Salesforce, from Setup, enter
Debug Modein the Quick Find box, then select Debug Mode Users.
Users with debug mode enabled have a check mark in the Debug Mode column.
In the user list, locate any users who need debug mode enabled. If necessary, use the standard list view controls to filter your org’s users.
Select the checkbox next to users for whom you want to enable debug mode.
To disable debug mode for a user, follow the preceding steps and click Disable instead of Enable.