This should do it: ( demo: https://www.mcrides.co.nz I have a “Weather” link )
You’ll need to style it with css.
customize->theme-></body
<script>
Discourse.ExternalNavItem = Discourse.NavItem.extend({
href : function() {
return this.get('href');
}.property('href')
});
I18n.translations.en.js.filters.premium = { title: "Premium", help: "Premium account" };
Discourse.NavItem.reopenClass({
buildList : function(category, args) {
var list = this._super(category, args);
if(!category) {
list.push(Discourse.ExternalNavItem.create({href: '/my/link.html', name: 'premium'}));
}
return list;
}
});
</script>