hugo-theme/layouts/partials/opengraph.html

<meta property="og:title" content="{{ if isset .Params "title" }}{{ print .Title " - " .Site.Title }}{{ else }}{{ .Site.Title }}{{ end }}" />
    {{- if and (eq .Type "blog") (not .IsSection) }}
    <meta property="og:type" content="article" />
    {{- else }}
    <meta property="og:type" content="website" />
    {{- end }}
    <meta property="og:image" content="" />
    <meta property="og:url" content="{{ .Permalink }}" />