Please check our Custom Shortcode tutorial from here – Create Custom Shortcode in WordPress

One last question. I want my product field to support a Shotcode so when i put a shortcode it works [myshortcode]

I’m not so sure where would i need to past this snap code ??
echo do_shortcode( get_post_meta( get_the_id(), ‘custom_field_key’, true ) );

Thank you

Thanks Oshi.
You should do the following modification at the above steps for adding radio buttons field into the custom meta box.
Step 2:
Add the radio buttons field array into the $custom_meta_fields variable like below.

// Custom meta fields array
$prefix = 'custom_';
$custom_meta_fields = array(
    array(
        'label'=> 'Gender',
        'desc'  => 'Choose the author gender',
        'id'    => $prefix.'author_gender',
        'type'  => 'radio',
        'options' => array(
            'Male' => 'Male',
            'Female' => 'Female'
        )
    )
);

Add the radio buttons field HTML into the show_custom_meta_box() callback function. Into the switch statement add the following case.

// radio button field
case 'radio':
    foreach($field['options'] as $val=>$label):
        echo '<input type="radio" name="'.$field['id'].'" id="'.$field['id'].'" value="'.$val.'" ',$meta ? ' checked="checked"' : '',' />
            <label for="'.$field['id'].'">'.$label.'</label>&nbsp;';
    endforeach;
    echo '<br /><span class="description">'.$field['desc'].'</span>';
break;

Now you can see the radio buttons field into the Custom Meta section at the post add/edit page.
Step 4:
You need to use the below code for display the radio buttons value.

$post_author_gender = $meta['custom_author_gender'][0];
echo 'Gender: '.$post_author_gender