Why isn't my header text being centered?

Why isn't my header text being centered?
0
#1

I’m working on my portfolio, and I don’t know why my header text isn’t being centered with the code below?

<h1 class = "text-center"> Daniel's Portfolio </h1>
#2

Have you imported Bootstrap in your code?

Do you have a codepen link?

#3

Forget to import Bootstrap. Works now!