Centering a do_shortcode?

Hello there,

I have a plugin that lets me monitor ads as long as I use a shortcode. I have added one into the header.php of my website, but it’s left-aligned:
https://citysavvyluxembourg.com/
Could anyone tell me how to center it, please? This is the code I put in the header php:-
echo do_shortcode( ‘[uam_ad id=”14341″]’ );

Many thanks in advance!