Search in your html file this code block. Copy and paste a list item to add a new nav.
<nav> <ul class="navs-list l-tal-c"> <li class="nav-item js-nav-item"> <a href="/index.php?action=artikel&lang=en&cat=18&id=77&artlang=en#products"><p class="nav-text t-fw-l">Products</p></a> </li> <li class="nav-item js-nav-item"> <a href="/index.php?action=artikel&lang=en&cat=18&id=77&artlang=en#ingredients"><p class="nav-text t-fw-l">Ingredients</p></a> </li> <li class="nav-item js-nav-item"> <a href="/index.php?action=artikel&lang=en&cat=18&id=77&artlang=en#team"><p class="nav-text t-fw-l">Team</p></a> </li> <li class="nav-item js-nav-item"> <a href="/index.php?action=artikel&lang=en&cat=18&id=77&artlang=en#about"><p class="nav-text t-fw-l">About</p></a> </li> <li class="nav-item js-nav-item"> <a href="/index.php?action=artikel&lang=en&cat=18&id=77&artlang=en#contact"><p class="nav-text t-fw-l">Contact</p></a> </li> </ul> </nav>
Anchor href attribute must match an id of a block, where page will scroll to on click.