Image upload on options WP page

options-script.js

jQuery( document ).ready(function($) {    
    //image option 
     $('body').on( 'click', '.muna-upl', function(e){
        e.preventDefault();
        var button = $(this),
            custom_uploader = wp.media({
                title: 'Insert image',
                library : {
                    // uploadedTo : wp.media.view.settings.post.id, // attach to the current post?
                    type : 'image'
                },
                button: {
                    text: 'Use this image' // button label text
                },
                multiple: false
            }).on('select', function() { // it also has "open" and "close" events
                var attachment = custom_uploader.state().get('selection').first().toJSON();
                button.html('<img src="' + attachment.url + '">').next().show().next().val(attachment.id);
            }).open();
    });

    // on remove button click
    $('body').on('click', '.muna-rmv', function(e){
        e.preventDefault();
        var button = $(this);
        button.next().val(''); // emptying the hidden field
        button.hide().prev().html('Upload image');
    });    
});

options.php

function muna_custom_settings() {
        //options image
        register_setting( 'muna_options_group', 'author_avatar');
        
        add_settings_section(
            'muna_options_section',
            esc_html__( 'Muna theme admin settings', THEME_NAME ),
            'settings_section_cb',
            'muna-options'
        );

        //options image
        add_settings_field('author_avatar', esc_html__( 'Choose author avatar', THEME_NAME ), 'author_avatar_settings_field_cb', 'muna-options', 'muna_options_section', array('label_for' => 'author_avatar'));
    }    

    //options image
    function author_avatar_settings_field_cb() {
        $image_id = get_option( 'author_avatar' );
    
        if( $image = wp_get_attachment_image_src( $image_id ) ) {
    
            echo '<a href="#" class="muna-upl"><img src="' . $image[0] . '" /></a>
              <a href="#" class="muna-rmv">Remove image</a>
              <input type="hidden" name="author_avatar" value="' . $image_id . '">';
    
        } else {
    
            echo '<a href="#" class="muna-upl">Upload image</a>
              <a href="#" class="muna-rmv" style="display:none">Remove image</a>
              <input type="hidden" name="author_avatar" value="">';
    
        }
    }
    
    //get image 
    $option_avatar = wp_get_attachment_image_src(get_option('author_avatar'));
    $avatar =  $option_avatar ?  $option_avatar[0] : '';