Go to the plugin folder: /wp-content/plugins/etsy-shop/
Edit the php file: etsy-shop.php
Find the following code:
<div class=”etsy-shop-listing-card” id=”‘ . $listing_id . ‘” style=”width:’ . $width . ‘”>
Replace ‘.$width.’ with your desired width and end with semicolon.
e.g. <div class=”etsy-shop-listing-card” id=”‘ . $listing_id . ‘” style=”width:200px;”>