How to create a custom extension

This is an example on how to create a custom extension in Advanced Sermons

// Custom extension module for example
add_action('asp_modules_content', 'custom_module_example');
function custom_module_example($modules) {
	?>
    <div class="asp-module">
        <div class="asp-module-box">
            <div class="module-heading">
                <h2 class="module-title">Custom Module</h2>
                <p>Enable the Custom Module to add extra functionality to your sermons.</p>
            </div>

            <div class="status wp-clearfix">
                <label class="asp-switch">
                    <input type="checkbox" name="asp_modules[custom_module]" value="1" <?php checked(isset($modules['custom_module'])); ?> />
                    <span class="asp-slider round"></span>
                </label>
                <span>Enable</span>
            </div>
        </div>
    </div>
	<?php
}