After GitHub Desktop installation my commit's author changed

I installed Github Desktop to my computer and then author of my commits changed. It was like this:
And became this:

How can I fix it?

Github uses the commit mail address to match your commits with your account. To make your username and avatar appear again you need to set the commit email address on your system, or, if it’s already correct, add that mail address to your Github account.

I’m not familiar with Github Desktop, so I don’t know why installing it would change the setting. Maybe someone else can answer that?

@alpceylan GitHub Desktop uses the name and email found in your .gitconfig. You can change this by going to the menu in GitHub Desktop and selecting File > Options > Git. Installing the app should not change this unless your name and email were not previously set in your .gitconfig, and in that case GitHub Desktop autofills with the name and email address from your GitHub account. I hope that helps!

I fixed it thank you Steve