Developper Lost on promoting SaaS

I'm a full technical guy and for 2 years with my coworker, we work on a recommendation engine for e-commerce powered by IA (https://zerecommender.com). Finally, it has been published on Shopify a few days ago (https://apps.shopify.com/zerecom...) and I am a bit confused about how to get my first users. Do you have some guidance or some content I can read to promote this kind of product?