FOSS Headlless E-commerce Shopify Next.js BE help

I am building a headless CMS for a Next.js custom FE and a shopify back end, I can do all the front end work, but I want to ensure I have the API keys, calls / mutations and checkout set up securely. It will probably be only a few hours work, where ideally I am on the call and you are walking me through it. You can see the FOSS template here: https://github.com/kiwihodl/sovereign-university If you are familiar to NOSTR, let me know, that's where this will pivot to eventually.