Open Table Widget not centering

I am trying to center this Open Table link.

Can anyone advise why this is aligning to the left.

script type=‘text/javascript’ src=‘//www.opentable.co.uk/widget/reservation/loader?rid=333648&type=standard&theme=tall&color=8&dark=false&iframe=true&domain=couk&lang=en-GB&newtab=false&ot_source=Restaurant%20website&font=arialBlack&ot_logo=standard&primary_color=ffffff&primary_font_color=333333&button_color=da3743&button_font_color=ffffff&cfe=true