Hiya, @milan-agatonovic ! Welcome to the FusionAuth community.
Here's a forum post about shopify integration: https://fusionauth.io/community/forum/topic/791/shopify-integration
The short answer is it should be possible, but unfortunately we don't have step by step instructions on how to do this. Hopefully the above forum post will give you some starting points.
Please feel free to post back with specific questions or progress. It's definitely something I'm interested in following along with.