Center category

Can you please let us know in detail, where you want to center the category? Please let us know with the screengrab along with the URL of that post. So that we will let you know back accordingly.

Can you please add the below CSS in the WordPress Dashboard -> Navigate to AMP Option Panel -> Design -> Global -> In the Advanced section Paste your Custom CSS and then click on the “Save Changes” button and let us know back?

span.amp-cat.amp-cat-2 {
    margin: 50%;
}