How to load different items from a drop-down menu?

I am trying to get data from this website and some items have a drop-down menu for different sizes. I need to get the MPN from each item. I have tried every option under the sun to get this to work and I have nothing. I copied my latest sitemap into here, but it's probably all wrong entirely.

I thought I would be able to click them as links, but I can't.

Any help??

Url: https://scubapro.johnsonoutdoors.com/dive-wear/wetsuits/definition-shorty-25mm-men-2019

Sitemap:
{"_id":"scubapro2","startUrl":["https://www.scubapro.com/"],"selectors":[{"id":"category-link","type":"SelectorLink","parentSelectors":["_root"],"selector":"li:nth-of-type(1) a.brand-image-lvl2","multiple":true,"delay":0},{"id":"scroll-to-load","type":"SelectorElementScroll","parentSelectors":["category-link"],"selector":".block-system > div","multiple":false,"delay":0},{"id":"product-link","type":"SelectorLink","parentSelectors":["scroll-to-load"],"selector":".title a","multiple":true,"delay":0},{"id":"mpn-text","type":"SelectorText","parentSelectors":["product-link"],"selector":"div.pdp-itemnumber","multiple":false,"regex":"","delay":0},{"id":"title-text","type":"SelectorText","parentSelectors":["product-link"],"selector":"h1","multiple":false,"regex":"","delay":0},{"id":"overview-html","type":"SelectorText","parentSelectors":["product-link"],"selector":".field-name-field-shortdescription div.field-item","multiple":false,"regex":"","delay":0},{"id":"features-text","type":"SelectorHTML","parentSelectors":["product-link"],"selector":"div.product-features-combined","multiple":false,"regex":"","delay":0},{"id":"specs-html","type":"SelectorHTML","parentSelectors":["product-link"],"selector":".materials-container div.tab-content","multiple":false,"regex":"","delay":0},{"id":"main-image","type":"SelectorImage","parentSelectors":["product-link"],"selector":".pdp-carousel-display img","multiple":false,"delay":0},{"id":"support-links","type":"SelectorLink","parentSelectors":["product-link"],"selector":".button-download a","multiple":true,"delay":0}]}

This site uses Ajax which redirects to a different URL for each size (the number at the end changes). So WS would have problems navigating it. The URLs for each size are actually embedded in the HTML source. If you could extract those and build a separate list of size URLs, then you could use them for a WS sitemap.