Loyalty program integration between Wix and my POS

I have a gaming and hobby shop with an experience centre and I used Wix to build my website. I am building an online community with a forum and access to online courses, which is super simple with Wix. I currently have Wix ‘site members’ which allows for them to use their account to access the online community and it also allows them to collect points automatically when they purchase online. My issue is, that Wix does not offer a POS system (in Australia yet) so for in-store I have a Square POS system. When customers purchase in-store, I don’t want them to have to re-sign up for a separate account, and I want their points to roll over onto their online account. Does anyone have some insight into how I could do that? TIA