Customize the head navigation bar

You can add the html element to the top navigation bar, open app/Admin/bootstrap.php

use OpenAdmin\Admin\Facades\Admin;

Admin::navbar(function (\OpenAdmin\Admin\Widgets\Navbar $navbar) {

    $navbar->left('html...');

    $navbar->right('html...');

    // adds fullscreen option
    $navbar->right(new OpenAdmin\Admin\Widgets\Navbar\Fullscreen());

    // adds ajax refresh button
    $navbar->right(new OpenAdmin\Admin\Widgets\Navbar\RefreshButton());

});

method left nad right is used to add the contents of the left and right sides of the head, the method parameters can be any object can be rendered( objects which impletements HtmlableRenderable, or has method __toString()) or strings.

Add elements to the left

For example, add a search bar on the left, first create a view resources/views/admin/search-bar.blade.php

<style>

    .search-form {
        width: 250px;
        border-radius: 3px;
        float: left;
        height:auto;
    }

    .search-form .input-group{
        padding-top:0.825rem;
    }

    .search-form input[type="text"] {
        color: #666;
        height:2.3rem;
    }

    .search-form .btn {
        height:2.3rem;
        border-color:#ced4da;
    }

</style>

<form action="/admin/pages" method="get" class="search-form" pjax-container>
    <div class="input-group input-group-sm">
        <input type="text" name="title" class="form-control" placeholder="Search...">
        <button type="submit" name="search" id="search-btn" class="btn btn-outline-primary"><i class="icon-search"></i></button>
    </div>
</form>

Then add it to the head navigation bar:

$navbar->left(view('admin.search-bar'));

Add elements to the right

You can only add the <li> tag on the right side of the navigation, such as adding some prompt icons, creating a new rendering class app/Admin/Extensions/Nav/Links.php

<?php

namespace App\Admin\Extensions\Nav;

class Links
{
    public function __toString()
    {
        return <<<HTML

<li class="nav-item">
    <a href="#" class="nav-link">
      <i class="icon-envelope"></i>
      <span class="badge bg-success">4</span>
    </a>
</li>

<li class="nav-item">
    <a href="#" class="nav-link">
      <i class="icon-bell"></i>
      <span class="badge bg-warning">7</span>
    </a>
</li>

<li class="nav-item">
    <a href="#" class="nav-link">
      <i class="icon-flag"></i>
      <span class="badge bg-danger">9</span>
    </a>
</li>

HTML;
    }
}

Then add it to the head navigation bar:

$navbar->right(new \App\Admin\Extensions\Nav\Links());

Or use the following html to add a drop-down menu:

<style>
    .notify-menu{
        line-height:2rem;
    }
</style>
<li class="nav-item dropdown ">
    <a href="#" class="nav-link dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">
        <i class="icon-bell"></i>
        <span class="badge bg-warning">10</span>
    </a>

    <ul class="dropdown-menu notify-menu">

    <li><h2 class="dropdown-header">You have 10 notifications</h2></li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-users text-info"></i> 5 new members joined today
        </a>
    </li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-exclamation-triangle text-warning"></i> Very long description here that may not fit into the page and may cause design problems
        </a>
    </li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-users text-danger"></i> 5 new members joined
        </a>
    </li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-shopping-cart text-success"></i> 25 sales made
        </a>
    </li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-user text-info"></i> You changed your username
        </a>
    </li>
    <li><hr class="dropdown-divider"></li>
    <li>
        <a class="dropdown-item" href="#">
        <i class="icon-arrow-alt-circle-right text-secondary"></i>View all</a>
    </li>
    </ul>
</li>

More components can be found here Bootstrap 5: Navbar