Help with a client who needs a "custom fit" tool

Hi, I'm working with an apparel client who would like to offer custom-fit clothing. I was wondering if anyone knew of a third-party tool like this to integrate into a squarespace site. Alternatively, if there isn't a ready-made tool, are there any developers out there who would quote building one for me? Thanks. Example of something simple from a shopify site https://www.leadinglady.com/pages/find-your-fit