The Todoist Completed Tasks plugin allows users to seamlessly integrate their completed tasks from Todoist into Obsidian notes. By specifying start and end segments in a note, users can fetch completed tasks for today, the past N hours, or based on custom date ranges. The plugin supports customizable prefixes and postfixes for tasks, making it compatible with other task management tools like Obsidian Tasks. With features designed to enhance task tracking within notes, it provides a streamlined way to manage completed Todoist tasks directly in Obsidian.