Custome js do not load

Did it in another way :stuck_out_tongue:

This post is the same question:
https://discourse.gohugo.io/t/how-to-include-a-script-on-only-one-content-page/20977

I have added an if statement to my footer like this:

<footer class="site-footer">
  <div class="container">
    <div class="row">
      <div class="col-12">
        <div class="site-footer-logo">
          <a href="{{ .Site.BaseURL }}">
            <img src="{{ .Site.Params.logo_footer | absURL }}" alt="logo-footer">
            <span class="brand-logo-footer">Kettenbeil</span>
          </a>
        </div>
      </div>
      {{ with .Site.Params.footer.contactInfo }}
      <div class="col-lg-3 col-md-6">
        <div class="site-footer-widget">
          <h5 class="site-footer-widget-title">{{ .title }}</h5>
          <p class="site-footer-widget-description">
	    {{ if .address }}
              {{ .address | safeHTML }}
	      <br>
	    {{ end }}
	    {{ if .phone }}
              <a href="tel:{{ .phone }}">{{ .phone }}</a>
              <br>
	    {{ end }}
	    {{ if .email }}
              <a href="mailto:{{ .email }}">{{ .email }}</a>
	    {{ end }}
          </p>
        </div>
      </div>
      {{ end }}
      {{ with .Site.Params.footer.sitemap }}
      <div class="col-lg-2 col-md-6">
        <div class="site-footer-widget">
          <h5 class="site-footer-widget-title">{{ .title }}</h5>
          <ul class="site-footer-widget-links">
            {{ range .link }}
            <li><a href="{{ .url | absURL }}">{{ .name }}</a></li>
            {{ end }}
          </ul>
        </div>
      </div>
      {{ end }}
      {{ with .Site.Params.footer.social }}
      <div class="col-lg-2 col-md-6">
        <div class="site-footer-widget">
          <h5 class="site-footer-widget-title">{{ .title }}</h5>
          <ul class="site-footer-widget-links">
            {{ range .link }}
              <li><a href="{{ .url }}">{{ .name }}</a></li>
            {{ end }}
          </ul>
        </div>
      </div>
      {{ end }}
      {{ with .Site.Params.footer.service }}
      <div class="col-lg-3 col-md-6">
        <div class="site-footer-widget">
          <h5 class="site-footer-widget-title">{{ .title }}</h5>
          <p class="site-footer-widget-description">
            {{ .description | safeHTML }}
          </p>
        </div>
      </div>
      {{ end }}
      <div class="col-lg-2 col-12">
        <a href="#top" class="site-footer-widget-top">
          <img src="{{ "images/to-top.svg" | absURL }}" alt="back-to-top">
          <p>
	    {{ .Site.Params.footer.back_to_top.description | safeHTML }}
          </p>
        </a>
      </div>
      <div class="col-12">
        <div class="site-footer-copyright">
          <p>© Copyright {{ dateFormat "2006" now }} - All Rights Reserved by <a href="https://staticmania.com/" target="_blank">StaticMania</a> </p>
        </div>
      </div>
    </div>
    {{ if .Site.Params.footer.qr_print }}
    <div class="row d-none d-print-block">
      <div class="col col-lg-2">
        {{ $qrcode := resources.Get "js/qrcode.js" | minify }}
        <script src="{{ $qrcode.Permalink }}"></script>

        <div id="qrcode">
          <script type="text/javascript">
           new QRCode(document.getElementById("qrcode"), {
             text: "{{ .Page.RelPermalink | absURL }}",
             width: 128,
             height: 128,
           });
          </script>
        </div>
      </div>
      <div class="col col-md-auto">
        {{ .Page.RelPermalink | absURL }}
      </div>
    </div>
    {{ end }}
  </div>
</footer>


<!-- {{ $formhandler := resources.Get "js/formhandler.js" | minify }}
<script src="{{ $formhandler.Permalink }}"></script> -->
{{ $vendor := resources.Get "js/vendor.js" | minify }}
<script src="{{ $vendor.Permalink }}"></script>
{{ $script := resources.Get "js/script.js" | minify }}
<script src="{{ $script.Permalink }}"></script>

{{ if $.Param "videoTest" -}}
{{ $video := resources.Get "js/video.js" | minify }}
<script defer src="{{ $video.RelPermalink }}"></script>
{{ end -}}

and then set videoTest in content → _index.md to true

---

title: "Home"

videoTest: true

---

Got it from this repo:
https://github.com/frjo/hugo-theme-zen/blob/2117479a0bc564a061a42013ef173d5ff9bd3326/layouts/partials/scripts.html#L11-L14

Maby not the right/correct way… but I understand it.
The Mermaid example is a bit complicated. Maby someone can explain it better?