Some merchants may want to display their product GTIN information on the product listing page. This can typically be done by simply adding the variable [gtin] on the listing_x.html template. However, this variable by itself will only ever show the main product's GTIN number. For products with advanced options - each with their own GTIN - the [gtin] variable alone won't work.
Beginning with version 7.6.0 of the Shift4Shop software, merchants can edit their listing template to show not only the main GTIN, but also have it update to the GTIN for the product variants as they are selected!
To do this, you will need to edit your listing_x.html template to include the following code block:
<div class="product-gtin">[product_gtin]:<span id="product_gtin">[gtin]</span></div>
Where to place the code is really a matter of preference, but the most ideal location will be just before the "<!--START: PRODUCT_FEATURES_BLOCK->" line.