Trade pricing / Wholesale

Could you give me a little pointer? Im not sure where that would go. I know it'll be simple )

Ok, am I on the right lines here

<?php if (perch_member_has_tag('tier1')) { 
        perch_shop_set_discount_code('ABC123');
    }; 
    ?>

and will that work just placed below

<? perch_shop_cart(); ?>

in my cart.php page ?

I have placed code as above but the cart is no longer loading. I'm not great with PHP. Is there more I should have done?

It's displaying nothing more than my header. So everything from above the code I've placed. Debug has disappeared too.

Here's my cart.php.. it's basic..

<?php if (!defined('PERCH_RUNWAY')) include($_SERVER['DOCUMENT_ROOT'].'/perch/runtime.php'); ?>

<?php perch_layout('global/header', [
   'body-class' => 'home',
]); ?>

    <?php if (perch_member_has_tag('tier1')) { 
        perch_shop_set_discount_code('ABC123');
    }; 
    ?>

   <? perch_shop_cart(); ?>

    <?php perch_layout('global/footer'); ?>

Hi I've been using the debug but thats not showing now. How do I access the error log? I'm assuming the command line but unsure of the command to use. I'm on a mac and using MAMP.

I found this

PHP Fatal error: Call to undefined method PerchShop_Cache::set_discount_code()

Here's the complete line from project folder path
[12-Jul-2016 17:22:04 Europe/London] PHP Fatal error: Call to undefined method PerchShop_Cache::set_discount_code() in /perch/addons/apps/perch_shop/lib/PerchShop_Runtime.class.php on line 184

Keep me posted when you do.
Thanks Drew

Brilliant! Thanks again )