I am new guy in OpenProject and I have a case that I want to ask

Imagine that I have a Task and I can finish the task in 3 days. Unfortunately,  I got new Important task to do and delay my first Task. I continued my first Task and finished in 5 days in total.

My boss clearly saw my Task completed in 5 days even though I could finish it in 3 days (Estimated)

How to implement the case of distraction to Gantt Chart?