How can I see updated source file?

I am currently following a tutorial about A.I UE4 C++/Blueprint AI Basics Part 3: Patrol/Chase Bot - YouTube.
In the video 9:50 he enters #include "BotMovementCharacter. When i enter it, the source file no longer exist. Does it means it got updated? If so where can i find the updated source file name?

It’s a file he has created himself. He said “it’s just a character”, so you want to create a new ACharacter-C+±Class.

Edit: I just saw the date of this question - you have probably figured it out already =)