Horizontal scroll for ul

I need to make a container with 3 rows and 3 columns so that I can scroll to the right.

How can i do this?

I tried to do white-space: nowrap; and overflow-x: auto;

But in this case, 1 row and 3 columns are obtained.

My codepen: https://codepen.io/oksromn/pen/zgpJNe